A Locus for Autosomal Dominant Posterior Polar Cataract on Chromosome 1p

Abstract

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 genetic linkage analysis using microsatellite markers in a three-generation pedigree. After exclusion of 13 known loci and candidate lens genes for autosomal dominant cataract, we obtained significantly positive LOD scores for markers D1S508 (Z = 3.14, θ = 0) and D1S468 (Z = 2.71, θ = 0). Multipoint analysis gave a maximum LOD score of 3.48 (θ = 0.07) between markers D1S508 and D1S468 . From haplotype data, however, CPP probably lies in the telomeric interval D1S2845 -1pter, which includes the locus for the clinically distinct Volkman congenital cataract ( CCV ). This study provides the first evidence for genetic heterogeneity of autosomal dominant posterior polar cataract for which a locus had been linked previously to chromosome 16q.