[Autosomal dominant congenital nuclear cataract caused by a deletion mutation in the beta A1-crystallin gene].

OBJECTIVE: To identify the genetic defect causing automosal dominant congenital cataracts (ADCC) with nuclear opacities in a Chinese pedigree. METHODS: Linkage analysis was carried out with the short tandem repeat polymorphisms flanking the candidate genes. Mutation analysis of the candidate gene in the critical region was performed to detect the potential mutation. RESULTS: The cataract locus in this pedigree was mapped to 17q11.1-12, an 11.78 cM interval between markers D17S933 and D17S 1288. By means of sequencing the candiate gene, betaA1-crystallin (CRYBA1), a deletion mutation DeltaG91 in exon 4 was detected. This change cosegregated with the patients in the family but was not found in 50 normal unrelated individuals. CONCLUSION: It is a deletion mutation DeltaG91 of CRYBA1 gene that causes autosomal dominant congenital nuclear cataract. This is the first report of an autosomal dominant congenital nuclear cataract caused by the mutation in this gene.