Identification of a novel mutation of the gene for gap junction protein alpha 3 (GJA3) in a Chinese family with congenital cataract

• Published in: Molecular biology reports Vol. 41; no. 7; pp. 4753 - 4758
• Main Authors: Hu, Ying, Gao, Lin, Feng, Yali, Yang, Tao, Huang, Shangzhi, Shao, Zhengbo, Yuan, Huiping
• Format: Journal Article
• Language: English
• Published: 01.07.2014
• ISSN: 0301-4851; 1573-4978
• DOI: 10.1007/s11033-014-3346-8

Cataract, defined as any opacity of the crystallin lens, can be divided into early onset (congenital or infantile) and age-related. It is the leading cause of visual disability in children, and mutations in many genes have currently been linked with this disorder. In the present study, we identified a genetic defect in a Chinese family with congenital cataract. Genomic DNA was extracted from the venous blood of the family and 100 normal controls. To screen for the disease-causing mutation, we sequenced eight candidate genes, and to predict the functional consequences of the mutation, a structural model of the protein was developed using the Protein Data Bank and PyMOL 1.1r1. We found a novel variant (c.163 A > G transition) in the gene for gap junction protein alpha 3, or the connexin46 gene. This mutation resulted in the substitution of a highly conserved asparagine at codon 55 by aspartic acid (p.N55D). There were no nucleotide polymorphisms in the other candidate genes sequenced.