A LOCUS FOR AUTOSOMAL-DOMINANT POSTERIOR POLAR CATARACT ON CHROMOSOME1P

Autosomal dominant congenital cataract is a clinically and genetically heterogeneous lens disease, Here we report the linkage of a locus for autosomal dominant posterior polar cataract (CPP) to the distal short arm of chromosome 1, To map the CPP locus we performed molecular gene tic linkage analysis using microsatellite markers in a three-generatio n pedigree, After exclusion of 13 known loci and candidate lens genes for autosomal dominant cataract, we obtained significantly positive LO D scores for markers D1S508 (Z = 3.14, theta = 0) and D1S468 (Z = 2.71 , theta = 0), Multipoint analysis gave a maximum LOD score of 3.48 (th eta = 0.07) between markers D1S508 and D1S468, From haplotype data, ho wever, CPP probably lies in the telomeric interval D1S2845-1pter, whic h includes the locus for the clinically distinct Volkman congenital ca taract (CCV), This study provides the first evidence for genetic heter ogeneity of autosomal dominant posterior polar cataract for which a lo cus had been linked previously to chromosome 16q.