Ophthalmologic heterogeneity in subjects with gyrate atrophy of choroid and retina harboring the L402P mutation of ornithine aminotransferase.
OBJECTIVE
To investigate clinical variation in a genetically homogenous group of subjects with gyrate atrophy of choroid and retina with hyperornithinemia (GA). The group was made up of homozygotes and compound heterozygotes for mutation L402P in the ornithine aminotransferase (OAT) gene.


METHODS
Cross-sectional study.


METHODS
Thirty-five Finnish subjects (18 men) with GA with a mean age of 33 years (range, 5-74 years) carrying the Finnish founder mutation L402P.


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 corneal electroretinography (ERG) recordings.


METHODS
The changes in eye fundi, visual acuity, cataract changes in the lens, visual field constriction, and ERG responses were determined.


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 phenotypic variation. Despite the great interindividual variation, both eyes of each subject were always similarly affected.


CONCLUSIONS
This study of 35 subjects with GA carrying a single mutation shows that the ophthalmologic symptoms and findings vary widely. The data also reveal that GA subjects are already affected by severe visual impairment in young adulthood. However, the diagnosis is often made very late.
Peltola
K E
KE
Department of Pediatrics, University of Turku, Kiinamyllynkatu 10, FIN-20520 Turku, Finland. katja.peltola@utu.fi
Näntö-Salonen
K
K
Heinonen
O J
OJ
Jääskeläinen
S
S
Heinänen
K
K
Simell
O
O
Nikoskelainen
E
E
D000293:Adolescent; D000328:Adult; D002386:Cataract / Q000175:diagnosis; D002648:Child; D002675:Child, Preschool; D002829:Choroid / Q000473:pathology*; D003430:Cross-Sectional Studies; D004596:Electroretinography; D005260:Female; D018740:Genetic Heterogeneity; D005838:Genotype; D015799:Gyrate Atrophy / Q000097:blood / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009216:Myopia / Q000175:diagnosis; D009952:Ornithine / Q000097:blood; D009953:Ornithine-Oxo-Acid Transaminase / Q000235:genetics*; D012160:Retina / Q000473:pathology*; D014792:Visual Acuity; D058609:Visual Field Tests; D014794:Visual Fields
D009952:Ornithine; D009953:Ornithine-Oxo-Acid Transaminase