Mutation analysis of congenital cataract in a Chinese family identified a novel missense mutation in the connexin 46 gene (GJA3)

摘要

Purpose: To identify the genetic defectsin a three-generation Chinese family with congenital nuclear cataract. Methods: Four patients and three healthymembers from the family underwent complete physical and ophthalmicexaminations. Genomic DNA was extracted from peripheral bloodleukocytes of the family members as well as from 100 healthy normalcontrols. Polymerase chain reaction (PCR) amplification and directsequencing of all coding exons of candidate genes were performed. Thefunctional consequences of the mutation were analyzed with biologysoftwares. Results: A novel mutation (c.130GA)was identified in the connexin 46 gene (GJA3), which resulted inthe substitution of valine by methionine at the highly conserved codon44 of connexin 46. This mutation co-segregated among the affectedmembers of the family and was not observed in either unaffected membersor the 100 normal controls. Conclusions: This is a novel missensemutation identified in the first extracellular loop of connexin 46;this expands the mutation spectrum of GJA3 in association withcongenital cataract.