DOMINANT OPTIC ATROPHY, KJER TYPE - LINKAGE ANALYSIS AND CLINICAL-FEATURES IN A LARGE BRITISH PEDIGREE

Objectives: To perform DNA linkage studies in an extensive 5-generatio n British pedigree with dominant optic atrophy and to validate the eff icacy of domiciliary screening for affected members. Methods: Family m embers received a domiciliary examination based on corrected visual ac uity, color vision, visual field defects, and optic disc appearance; D NA linkage analysis was performed using 7 microsatellite markers on 3q 27-qter. Results: Based on the results of the ophthalmic examination, 15 members could be classified as definitely affected, 1 probably affe cted, and 25 unaffected. Two-point linkage analysis gave significant m aximum lod scores at u = 0.00, with the markers D3S3669, D3S3590, and D3S3642. A haplotype segregating with the disease was identified in af fected individuals, including the probably affected subject. Informati ve meioses defined the disease interval between markers D3S1601 and D3 S1265. Conclusions: Domiciliary screening was effective in identifying all 16 affected members of a British family with dominant optic atrop hy. The typical clinical features were present. The location of the OP A1 gene in this new British family seems to be in the 3q27-28 region a nd is the same as that reported in Danish, Cuban, and French families, suggesting no genetic heterogeneity in this disorder.