A Chinese family with progressive childhood cataracts and IVS3+1G>A CRYBA3/A1 mutations

PURPOSE: To characterize the disease-causing mutations in a Chinese family with progressive childhood cataracts. METHODS: Family history and clinical data were recorded. Direct gene sequencing together with multi-point linkage analysis using microsatellite markers flanking the gene was applied to identify the disease-causing mutation. RESULTS: Lens examination in the affected members revealed childhood cataracts along with progressive developing fetal nuclear lactescent cataracts with ‘Y’ sutural opacities, and also progressive developing peripheral cortical opacities. Direct gene sequencing showed a G>A transition at the donor splice site of intron 3 (IVS3+1 G>A) of the βA1/A3-crystallin gene (CRYBA3/A1) in this Chinese autosomal dominant childhood cataract family, and the maximum heterogeneity logarithm of odds (HLOD) score obtained by multi-point analysis was detected at marker locus D17S1800 (HLOD=3.005; α=1.000). CONCLUSIONS: To our knowledge, this is the first report of a phenotype of progressive nuclear and cortical cataracts related to the CRYBA3/A1 mutation IVS3+1 G>A. This finding expands the spectrum of cataract phenotypes caused by the IVS3+1 G>A mutation of CRYBA3/A1, confirms the phenotypic heterogeneity of this mutation and suggests the mechanism that influences the cataractogenesis in different ethnic backgrounds.