Abstract: Objective To identify the pathogenic gene in a southern Chinese family having autosomal dominant congenital cataract. Design Experimental study. Participants A Chinese family with hereditary nuclear cataract was enrolled. Method A Chinese family with inherited cataract treated at Beijing Tongren Hospital was recruited. Detailed family history was recorded. Blood was taken from the proband and available family members. Candidate genes sequencing was performed by sequencing of polymerase chain reaction (PCR) products. Bioinformatics analysis was then used to evaluate the effect of the amino acid change. Main Outcome Measures Gene sequences. Results Ophthalmologic examination showed that the congenital cataract phenotype of the family was nuclear cataract. Candidate genes sequencing revealed a C>G transition at position c.565 in the GJA8 gene. The mutation led to a Proline to Alanine substitution in position p.189 and was not found in unaffected family members and 100 unrelated controls. Bioinformatics analysis showed that the detected mutation was located within a highly conserved region and probably damaged the structure as well as function of GJA8 gene. Conclusions A novel GJA8 gene mutation was found to be associated with hereditary nuclear cataract in a Chinese ADCC family. The second extracellular domain of Cx50 may play an important role in maintaining the transparency of the lens. (Ophthalmol CHN, 2013, 22: 86-89)

Key words: congenital cataract, GJA8 gene, mutation, intercellular channel