Purpose: To detect the underlying genetic defect in a four-generation Chinese family affected with autosomal dominant congenital cataracts(ADCC).
Methods: The clinical data of patients from the family were recorded by slit-lamp photography. Genomic DNA samples were extracted from peripheral blood of the pedigree members. Mutation screening was performed in the nuclear and zonular pulverulent cataract-related gene by bidirectional sequencing of the amplified products.
Results: The congenital cataract phenotype of the pedigree was labeled as the nuclear and zonular pulverulent type by using slit-lamp photography. Sequencing of the candidate genes detected a heterozygous c.139G>C change in the coding region of the connexin50(Cx50)/gap junction protein alpha 8 gene (GJA8), resulting in the substitution of a highly conserved Aspartic acid by Histidine (p. D46H). This change was co-segregated with affected members of the pedigree,but not seen in all unaffected members and 100 unrelated control individuals.
Conclusions: This study has identified a novel Cx50 mutation, p. D46H in a Chinese family with nuclear and zonular pulverulent congenital cataracts.This mutation is probable causative lesion for the observed phenotype in this family.