Mapping of a novel locus associated with autosomal recessive congenital cataract to chromosome 8p

Purpose: To identify the disease locus for autosomal recessive congenital cataracts in a consanguineous Pakistani family. Methods: All affected individuals underwent a detailed ophthalmologic examination. Blood samples were collected and genomic DNA was extracted. A genome-wide scan was completed with fluorescently-labeled microsatellite markers on genomic DNA from affected and unaffected family members. Logarithms of odds (LOD) scores were calculated under a fully penetrant autosomal recessive model of inheritance. Results: Ophthalmic examination suggested that affected individuals have bilateral cataracts. Linkage analysis localized the critical interval to chromosome 8p with LOD scores of 3.19, and 3.08 at θ=0, obtained with markers D8S549 and D8S550, respectively. Haplotype analyses refined the critical interval to 37.92 cM (16.28 Mb) region, flanked by markers, D8S277 proximally and D8S1734 distally. Conclusions: Here, we report a new locus for autosomal recessive congenital cataract mapped to chromosome 8p in a consanguineous Pakistani family.