Understanding the Ultra-Rare Disease Autosomal Dominant Leukodystrophy: an Updated Review on Morpho-Functional Alterations Found in Experimental Models.

Autor: Neri I; Cellular Signalling Laboratory, Anatomy Centre, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, 40126, Bologna, Italy., Ramazzotti G; Cellular Signalling Laboratory, Anatomy Centre, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, 40126, Bologna, Italy., Mongiorgi S; Cellular Signalling Laboratory, Anatomy Centre, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, 40126, Bologna, Italy., Rusciano I; Cellular Signalling Laboratory, Anatomy Centre, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, 40126, Bologna, Italy., Bugiani M; Department of Pathology, Amsterdam University Medical Centers, Vrije Universiteit and Amsterdam Neuroscience, 1105, Amsterdam, The Netherlands., Conti L; Department of Cellular, Computational, and Integrative Biology (CIBIO), Università Degli Studi Di Trento, 38123, Povo-Trento, Italy., Cousin M; Center for Individualized Medicine and Department of Clinical Genomics, Mayo Clinic, Rochester, MN, 55905, USA., Giorgio E; Department of Molecular Medicine, University of Pavia, 27100, Pavia, Italy.; Medical Genetics Unit, IRCCS Mondino Foundation, 27100, Pavia, Italy., Padiath QS; Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, 15261, USA., Vaula G; Department of Neuroscience, Azienda Ospedaliera-Universitaria Città della Salute e della Scienza, 10126, Turin, Italy., Cortelli P; IRCCS, Istituto Di Scienze Neurologiche Di Bologna, 40139, Bologna, Italy.; Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, 40126 , Bologna, Italy., Manzoli L; Cellular Signalling Laboratory, Anatomy Centre, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, 40126, Bologna, Italy., Ratti S; Cellular Signalling Laboratory, Anatomy Centre, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, 40126, Bologna, Italy. stefano.ratti@unibo.it.

Publikováno v: Molecular neurobiology [Mol Neurobiol] 2023 Nov; Vol. 60 (11), pp. 6362-6372. Date of Electronic Publication: 2023 Jul 14.

Enhanced differentiation of the mouse oli-neu oligodendroglial cell line using optimized culture conditions.

Autor: Bey GR; Department of Human Genetics, School of Public Health, University of Pittsburgh, 130 De Soto St, Pittsburgh, PA, 15261, USA., Padiath QS; Department of Human Genetics, School of Public Health, University of Pittsburgh, 130 De Soto St, Pittsburgh, PA, 15261, USA. qpadiath@pitt.edu.; Department of Neurobiology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA. qpadiath@pitt.edu.

Publikováno v: BMC research notes [BMC Res Notes] 2023 Aug 04; Vol. 16 (1), pp. 161. Date of Electronic Publication: 2023 Aug 04.

scMAPA: Identification of cell-type-specific alternative polyadenylation in complex tissues.

Autor: Bai Y; Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA., Qin Y; Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA., Fan Z; Department of Computer Science, School of Computing and Information, University of Pittsburgh, Pittsburgh, PA 15213, USA., Morrison RM; Department of Medicine and Division of Hematology/Oncology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15213, USA.; Department of Immunology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15213, USA.; Department of Computational and Systems Biology, University of Pittsburgh Medical Center, Pittsburgh, PA 15213, USA., Nam K; Department of Environmental and Occupational Health, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA., Zarour HM; Department of Medicine and Division of Hematology/Oncology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15213, USA.; Department of Immunology, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15213, USA., Koldamova R; Department of Environmental and Occupational Health, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA., Padiath QS; Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA.; Department of Neurobiology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA., Kim S; Department of Pediatrics, School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15224, USA.; Division of Pediatric Pulmonary Medicine, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA., Park HJ; Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA.

Publikováno v: GigaScience [Gigascience] 2022 Apr 30; Vol. 11.

Deletion of conserved non-coding sequences downstream from NKX2-1: A novel disease-causing mechanism for benign hereditary chorea.

Autor: Liao J; Pittsburgh Cytogenetics Laboratory, Magee-Womens Hospital of UPMC, Pittsburgh, PA, USA.; Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA., Coffman KA; Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA., Locker J; Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA., Padiath QS; Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA., Nmezi B; Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA., Filipink RA; Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA., Hu J; Pittsburgh Cytogenetics Laboratory, Magee-Womens Hospital of UPMC, Pittsburgh, PA, USA.; Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh, Pittsburgh, PA, USA., Sathanoori M; Pittsburgh Cytogenetics Laboratory, Magee-Womens Hospital of UPMC, Pittsburgh, PA, USA.; Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.; Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh, Pittsburgh, PA, USA., Madan-Khetarpal S; Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA., McGuire M; Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA., Schreiber A; Genomic Medicine Institute, Cleveland Clinic, Cleveland, OH, USA., Moran R; Genomic Medicine Institute, Cleveland Clinic, Cleveland, OH, USA., Friedman N; Center for Pediatric Neurology, Cleveland Clinic, Cleveland, OH, USA., Hoffner L; Magee Womens Research Institute, University of Pittsburgh Medical Center, Pittsburgh, PA, USA., Rajkovic A; Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.; Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.; Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh, Pittsburgh, PA, USA.; Magee Womens Research Institute, University of Pittsburgh Medical Center, Pittsburgh, PA, USA., Yatsenko SA; Pittsburgh Cytogenetics Laboratory, Magee-Womens Hospital of UPMC, Pittsburgh, PA, USA.; Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.; Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.; Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh, Pittsburgh, PA, USA.; Magee Womens Research Institute, University of Pittsburgh Medical Center, Pittsburgh, PA, USA., Surti U; Pittsburgh Cytogenetics Laboratory, Magee-Womens Hospital of UPMC, Pittsburgh, PA, USA.; Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.; Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.; Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh, Pittsburgh, PA, USA.; Magee Womens Research Institute, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.

Publikováno v: Molecular genetics & genomic medicine [Mol Genet Genomic Med] 2021 Apr; Vol. 9 (4), pp. e1647. Date of Electronic Publication: 2021 Mar 05.

Cardiac phenotype in ATP1A3 -related syndromes: A multicenter cohort study.

Autor: Balestrini S; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Mikati MA; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy. s.sisodiya@ucl.ac.uk j.kaski@ucl.ac.uk mohamad.mikati@duke.edu., Álvarez-García-Rovés R; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Carboni M; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Hunanyan AS; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Kherallah B; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., McLean M; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Prange L; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., De Grandis E; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Gagliardi A; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Pisciotta L; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Stagnaro M; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Veneselli E; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Campistol J; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Fons C; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Pias-Peleteiro L; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Brashear A; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Miller C; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Samões R; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Brankovic V; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Padiath QS; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Potic A; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Pilch J; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Vezyroglou A; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Bye AME; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Davis AM; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Ryan MM; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Semsarian C; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Hollingsworth G; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Scheffer IE; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Granata T; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Nardocci N; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Ragona F; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Arzimanoglou A; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Panagiotakaki E; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Carrilho I; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Zucca C; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Novy J; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Dzieżyc K; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Parowicz M; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Mazurkiewicz-Bełdzińska M; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Weckhuysen S; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Pons R; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Groppa S; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Sinden DS; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Pitt GS; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Tinker A; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Ashworth M; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Michalak Z; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Thom M; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Cross JH; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Vavassori R; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy., Kaski JP; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy. s.sisodiya@ucl.ac.uk j.kaski@ucl.ac.uk mohamad.mikati@duke.edu., Sisodiya SM; From the Department of Clinical and Experimental Epilepsy (S.B., S.M.S.), UCL Queen Square Institute of Neurology, London; Chalfont Centre for Epilepsy (S.B., S.M.S.), Bucks, UK; Division of Pediatric Neurology (M.A.M., A.S.H., B.K., M.M., L.P.), Department of Neurobiology, and Division of Cardiology (M.C.), Department of Pediatrics, Duke University, School of Medicine, Durham, NC; Centre for Inherited Cardiovascular Diseases (R.A.G.-R., J.P.K.), Great Ormond Street Hospital for Children NHS Foundation Trust; Institute of Cardiovascular Science(R.A.G.-R., J.P.K.), University College London, London, UK; Child Neuropsychiatry Unit (E.D.G., A.G., L.P., M.S., E.V.), IRCCs Istituto Giannina Gaslini, Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health, DINOG-MI, University of Genoa; Department of Pediatric Neuroscience (A.G., T.G., N.N., F.R.), Fondazione IRCCS Istituto Neurologico Carlo Besta; Unit of Child Neuropsychiatry (L.P.), ASST Fatebenefratelli Sacco, Milan, Italy; Paediatric Neurology Department (J.C., C.F., L.P.-P., A.A.), Hospital Sant Joan de Déu, Esplugues de Llobregat, Barcelona University, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Barcelona, Spain; Department of Neurology (A.B., C.M.), Wake Forest School of Medicine, Winston-Salem, NC; Neurology Department (R.S.), Centro Hospitalar e Universitario do Porto-Hospital de Santo António, Porto, Portugal; Clinic for Child Neurology and Psychiatry (V.B., A.P.), Department of Child Neurology, Medical Faculty University of Belgrade, Serbia; Department of Human Genetics (Q.S.P.), Graduate School of Public Health, University of Pittsburgh, PA; Department of Pediatric Neurology (J.P.), Medical University of Silesia, Katowice, Poland; Clinical Neurosciences (K.V., J.H.C.), Developmental Neuroscience Programme, UCL Great Ormond Street Institute of Child Health, and Great Ormond Street Hospital for Children NHS Foundation Trust, Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, London, UK; Sydney Children's Hospital (A.M.E.B.), Randwick; Department of Cardiology (A.M.D.), The Royal Children's Hospital, Melbourne, University of Melbourne; Department of Neurology (M.M.R.), Royal Children's Hospital, Melbourne; Agnes Ginges Centre for Molecular Cardiology (C.S.), Centenary Institute, University of Sydney; Epilepsy Research Centre (G.H., I.E.S.), Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC; Department of Paediatrics (I.E.S.), University of Melbourne, Royal Children's Hospital, Florey and Murdoch Children's Research Institutes, Melbourne, Australia; Department of Clinical Epileptology, Sleep Disorders and Functional Neurology in Children (A.A., E.P.), University Hospitals of Lyon (HCL), Member of the International Alternating Hemiplegia in Childhood Research Consortium IAHCRC and of the European Reference Network ERN EpiCARE, Lyon, France; Paediatric Neurology Unit (I.C.), CMIN, Centro Hospitalar e Universitario Porto, Porto, Portugal; Clinical Neurophysiology Unit (C.Z.), IRCCS 'E. Medea,' Bosisio Parini (LC), Italy; Department of Neurology (J.N.), CHUV and Université de Lausanne, Switzerland; Second Department of Neurology (K.D.), Institute Psychiatry and Neurology, Warsaw, Poland; Association AHC18+ e. V. (Germany) and Polish Association for People Affected by AHC, ahc-pl (M.P.); Department of Developmental Neurology (M.M.B.), Medical University of Gdańsk, Poland; Neurology Department (S.W.), University Hospital Antwerp; Neurogenetics Group (S.W.), University Antwerp, Belgium; First Department of Pediatrics (R.P.), 'Agia Sofia' Children Hospital, National & Kapodistrian University of Athens, Greece; Department of Neurology (S.G.), University Medical Center of the Johannes Gutenberg University Mainz, Germany; Ion Channel Research Unit (D.S.S.), Department of Medicine/Cardiology and Pharmacology, Duke University Medical Center, Durham, NC; Cardiovascular Research Institute (G.S.P.), Weill Cornell Medical College, New York, NY; The Heart Centre (A.T.), Queen Mary University of London; Department of Pathology (M.A.), Great Ormond Street Hospital for Children NHS Foundation Trust; Department of Neuropathology (Z.M., M.T.), Institute of Neurology, University College London, UK; and ICT and Data Analysis Section (R.V.), Euro-Mediterranean Institute of Science and Technology (I.E.ME.S.T.), Palermo, Italy. s.sisodiya@ucl.ac.uk j.kaski@ucl.ac.uk mohamad.mikati@duke.edu.

Publikováno v: Neurology [Neurology] 2020 Nov 24; Vol. 95 (21), pp. e2866-e2879. Date of Electronic Publication: 2020 Sep 10.