A novel locus of coralliform cataract mapped to chromosome 2p24-pter

Congenital cataract is a common major abnormality of the eye, which can result in significant visual impairment or blindness in childhood. In this work, we studied four generations of a Chinese family that exhibited autosomal dominant coralliform cataract but no other ocular or systemic abnormalities. Members of the family were firstly genotyped with microsatellite markers at loci associated with congenital cataract on the reported regions of chromosomes 1, 2, 3, 10, 11, 12, 13, 15, 16, 17, 20, 21, and 22, but negative LOD scores were obtained. Following exclusion of these loci, a genome-wide scan was performed, and significant evidence of linkage was obtained for marker D2S2211 (Z = 2.69, theta = 0.00). In multipoint analysis, a maximum LOD score 4.87 (theta = 0.00) was reached between markers D2S2211 and D2S2164. Haplotype data indicated a coralliform cataract disease gene in a 26-cM interval at a novel disease locus 2p24-pter between D2S297 and D2S2268. No genes related to cataract in this region have been reported so far.