Subclinical maculopathy and retinopathy in transcobalamin deficiency: a 10-year follow-up.

Autor: Rigaudière F; Service de Physiologie Clinique. Explorations Fonctionnelles, DMU DREAM, Hôpital Lariboisière, AP-HP, Paris, France. rigaudiereflo@aol.com.; Faculté de Médecine Paris-Diderot, Université de Paris, Paris, France. rigaudiereflo@aol.com., Nasser H; Département de Génétique, Hôpital Robert Debré, AP-HP, Paris, France.; Explorations Fonctionnelles, Hôpital Robert Debré, AP-HP, Paris, France., Delouvrier E; Service d'Ophtalmologie, Hôpital Robert Debré, AP-HP, Paris, France., Milani P; Service de Physiologie Clinique. Explorations Fonctionnelles, DMU DREAM, Hôpital Lariboisière, AP-HP, Paris, France., Schiff M; Reference Center for Inborn Errors of Metabolism, Robert Debré Hospital, AP-HP, Paris, France.; Reference Center for Inborn Errors of Metabolism, Faculté de Médecine Paris-Descartes, Necker University Hospital, AP-HP, Université de Paris, Paris, France.; Institut Imagine, Inserm UMRS_1163, Paris, France.
Jazyk: angličtina
Zdroj: Documenta ophthalmologica. Advances in ophthalmology [Doc Ophthalmol] 2022 Feb; Vol. 144 (1), pp. 53-65. Date of Electronic Publication: 2021 Sep 07.
DOI: 10.1007/s10633-021-09849-5
Abstrakt: Introduction: Transcobalamin (TC) transports cobalamin (vitamin B 12 ) from plasma into cells. Its congenital deficiency is a rare autosomal recessive disorder due to mutations in the TCN2 gene. It causes intracellular cobalamin depletion with early onset in the first months of life, failure to thrive with pallor due to megaloblastic anemia. It can be associated with pancytopenia, gastrointestinal symptoms with vomiting, diarrhea, and neurological complications with myelopathy. Aggressive vitamin B12 parenteral therapy must be instituted early and continuously. Retinopathy and maculopathy are rarely associated with this condition.
Subject: We report the electrophysiological results of one TC-deficient patient diagnosed at the age of 4 months immediately and continuosly treated by hydroxocobalamin IM. Her visual function was followed by eight ophthalmological assessments, eight flash-ERG, six EOG, one mf-ERG, and seven P-ERG recordings over a 10-year period, between the age of 2y 9 m and 12y 6 m.
Results: Her ophthalmological assessment including visual acuity, fundi, optical coherent tomography (OCT), and retinal nerve fiber layer (RNFL) remained normal. From the age of 2y 9 m to 5y, dark-adapted and light-adapted flash-ERGs, EOGs and pattern-ERG were normal. From the age of 6y 4 m to 12y 6 m, dark-adapted flash-ERGs and EOGs remained normal. Cone a-wave amplitudes remained normal, whereas cone b-wave and flicker-response amplitudes were decreased. At the age of 12y 6 m, mf-ERG N1P1 amplitudes on the central 30° were decreased. From the age of 7y 4 m to 12y 6 m, P-ERG P50 amplitudes were decreased with no N95.
Comments: While clinical and anatomical assessments remained normal over a 10-year period, patient's electrophysiological results suggested the progressive onset of a subclinical retinopathy of inner-cone dystrophy type, and a subclinical maculopathy on the central 30° including the ganglion cell layer deficiency on the central 15°, despite continuous intramuscular treatment, RPE and scotopic system remaining normal. The origins of such subclinical retinopathy and maculopathy are unknown and independent of early disease identification and aggressive intramuscular hydroxocobalamin therapy.
(© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
Databáze: MEDLINE
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