A new congenital nuclear cataract caused by a missense mutation in the gammaD-crystallin gene (CRYGD) in a Chinese family.

PURPOSE

To identify genetic defects associated with nuclear golden crystal autosomal dominant congenital cataract (ADCC) in a Chinese pedigree in the north of China.

METHODS

Clinical data were collected and the phenotype of the affected members in this family was recorded by slit lamp photography. Genomic DNA was isolated from peripheral blood. Linkage analyses excluded all known loci except that in 2q33-q35. Mutation analysis of CRYGs was carried by direct sequencing of the PCR products.

RESULTS

Sequencing of the coding regions of CRYGA, CRYGB, CRYGC, and CRYGD showed the presence of a heterozygous C>A transversion at nt109 of the coding sequence (R36S) in exon 2 of CRYGD, which co-segregated with the affected members.

CONCLUSIONS

The R36S mutation in CRYGD identified in this Chinese family caused a nuclear golden crystal cataract phenotype not described before. This finding is an additional indication that there may be phenotypic heterogeneity of cataract, especially in different races.