RESUMO
PURPOSE: This study aimed to map the genetic locus responsible for a novel X-linked congenital cataract phenotype. METHODS: A large three-generation family with lamellar and nuclear cataract in five affected males was identified. Linkage analysis was conducted by genotyping X-chromosome specific microsatellite markers at an average spacing of 5 cM. Analysis was conducted using the LINKAGE package under an X-linked recessive model. RESULTS: A linkage was detected on Xq24 with the maximum LOD score of 2.53 at theta=0 for DXS1001. The minimal region was defined as 11.5 Mb between markers DXS8055 and DXS8009 through critical recombination events in multiple individuals. CONCLUSIONS: A gene causing this novel congenital cataract phenotype is located on the long arm of the X chromosome.