Ophthalmologic heterogeneity in subjects with gyrate atrophy of choroid and retina harboring the L402P mutation of ornithine aminotransferase

Objective/Purpose: To investigate clinical variation in a genetically homog enous group of subjects with gyrate atrophy of choroid and retina with hype rornithinemia (GA), The group was made up of homozygotes and compound heter ozygotes for mutation L402P in the ornithine aminotransferase (OAT) gene, Design: Cross-sectional study. Participants: Thirty-five Finnish subjects (18 men) with GA with a mean age of 33 years (range, 5-74 years) carrying the Finnish founder mutation L402 P, Methods: All subjects were examined between 1993 and 1995, The analysis was composed of, in addition to careful clinical evaluation, studies of visual fields with Goldmann perimeter, photographing of the eye fundi, and cornea l electroretinography (ERG) recordings, Main Outcome Measures: The changes in eye fundi, visual acuity, cataract ch anges in the lens, visual field constriction, and ERG responses were determ ined. Results: Myopia, early cataracts, and highly abnormal ERG were typical for the GA subjects. The changes progressed rather uniformly with age. However, visual acuity, funduscopic findings, and visual fields showed great phenot ypic variation, Despite the great interindividual variation, both eyes of e ach subject were always similarly affected. Conclusions: This study of 35 subjects with GA carrying a single mutation s hows that the ophthalmologic symptoms and findings vary widely, The data al so reveal that GA subjects are already affected by severe visual impairment in young adulthood. However, the diagnosis is often made very late. (C) 20 01 by the American Academy of Ophthalmology.