| Autor: |
Alsalloum A; Federal Research Center for Innovator and Emerging Biomedical and Pharmaceutical Technologies, 125315 Moscow, Russia., Mosin I; Pediatric City Clinical Hospital Named for Z.A. Bashlyaevoy, 129272 Moscow, Russia., Shefer K; S. Fyodorov 'Eye Microsurgery' Federal State Institution St. Petersburg Branch, 192283 St. Petersburg, Russia., Mingaleva N; Federal Research Center for Innovator and Emerging Biomedical and Pharmaceutical Technologies, 125315 Moscow, Russia., Kim A; Federal Research Center for Innovator and Emerging Biomedical and Pharmaceutical Technologies, 125315 Moscow, Russia., Feoktistova S; Federal Research Center for Innovator and Emerging Biomedical and Pharmaceutical Technologies, 125315 Moscow, Russia., Malyugin B; S.N. Fedorov National Ophthalmology Medical Research Center 'Eye Microsurgery', 127486 Moscow, Russia., Boiko E; S. Fyodorov 'Eye Microsurgery' Federal State Institution St. Petersburg Branch, 192283 St. Petersburg, Russia.; North-Western State Medical University Named after I.I. Mechnikov, 191015 St. Petersburg, Russia., Sultanov S; Artema Therapeutics Inc., Brooklyn, NY 11201, USA., Mityaeva O; Federal Research Center for Innovator and Emerging Biomedical and Pharmaceutical Technologies, 125315 Moscow, Russia.; Department of Fundamental Medicine, Lomonosov Moscow State University, 119992 Moscow, Russia., Volchkov P; Federal Research Center for Innovator and Emerging Biomedical and Pharmaceutical Technologies, 125315 Moscow, Russia.; Department of Fundamental Medicine, Lomonosov Moscow State University, 119992 Moscow, Russia.; Moscow Clinical Scientific Center N.A. A.S. Loginov, 111123 Moscow, Russia. |
| Abstrakt: |
Background/Objectives : Cone dystrophy with supernormal rod response (CDSRR) is a rare autosomal recessive retinal disorder characterized by a delayed and markedly decreased photoreceptor response. In this article, we aim to describe the clinical course and associated molecular findings in children with cone dystrophy with supernormal rod response associated with recessive mutations in the KCNV2 gene, which encodes a subunit (Kv8.2) of the voltage-gated potassium channel. Methods : The genetic testing of two patients included the next-generation sequencing of a retinal dystrophy panel and direct Sanger sequencing to confirm KCNV2 gene variants, in addition to an electroretinogram (ERG) and spectral domain optical coherence tomography (SD-OCT). Results : Cone dystrophy with supernormal rod response is associated with identified variants in the KCNV2 gene. The genetic analysis of the first case identified a compound heterozygous mutation in the KCNV2 gene, including a de novo nonsense duplication at cDNA position 1109, which led to the premature termination of the p.Lys371Ter codon in the second extracellular domain of the protein. Two patients showed changes in the full-field electroretinogram, especially in the first case, which demonstrated a close to supernormal total electroretinogram amplitude. This study increased the range of the KCNV2 mutation database, added an unreported de novo substitution pattern to KCNV2 gene variants, and linked it to the evaluated clinical studies. Conclusions : The initial clinical manifestations were varied, but both patients presented with hypermetropia and slight exotropia. The ERG findings are characteristic of KCNV2 mutations, and patients exhibited an increased b-wave latency in DA3.0 ERG (combined rod-cone response). |
