[Gene mapping and mutation detection in a family with congenital anterior polar cataract].

ABSTRACT

OBJECTIVE: To map the gene mutation responsible for autosomal dominant inherited congenital anterior polar cataract in a Chinese family. METHODS: Peripheral blood samples were collected from the members in this congenital cataract family. DNA was extracted from the blood samples. A gene scan was performed using approximately 400 microsatellite markers (ABI). Linkage analysis was processed to define the region of mutated gene. High density primers labeled with fluorescent stain for the positive region were adopted for fine targeting and haplotype analysis was performed. Mutation detection was carried out by sequencing candidate genes. RESULTS: The maximum two-point LOD score was obtained at D21S1252, Z(max) = 3.23 (θ(max) = 0.00). After fine targeting and haplotype analysis, the mutated gene was located within a 18.47 cM region between D21S263 and D21S266 on chromosome 21q22.11-q22.3. Direct sequencing of the candidate gene revealed a G©öA transition in exon 3 of CRYAA. CONCLUSION: The present study has identified a missense mutation in CRYAA associated with congenital anterior polar cataract in a Chinese family.