A novel mutation in the connexin 46 gene (GJA3) causes autosomal dominant zonular pulverulent cataract in a Hispanic family.

PURPOSE: A five-generation Hispanic pedigree with autosomal dominant zonular pulverulent cataract was studied to identify the causative mutation in connexin 46 (Cx46), a gap junction protein responsible for maintaining lens homeostasis.

METHODS

Twenty-six individuals from the family were comprehensively clinically examined. DNA was extracted from their peripheral blood samples. The DNA was used for automated genotyping with fluorescently labeled microsatellite markers and for mutation detection by automated sequencing.

RESULTS

A novel D3Y missense mutation in GJA3 segregated with autosomal dominant (AD) zonular pulverulent cataract throughout the family. The mutation was absent in the unaffected individuals in the family and in 230 control chromosomes.

CONCLUSIONS

A novel mutation causing AD zonular pulverulent cataract has been identified in a Hispanic Central American family. This is the first report of a mutation in GJA3 causing autosomal dominant congenital cataract (ADCC) in this ethnic group. It is also the first reported cataract-causing mutation in the NH2-terminal region of the Cx46 protein.