The Report for Genetic Analysis of Korean Families with Congenital Cataract

Kim, Hae Sook; Song, In Kyung; Yu, Young Suk; Kim, Hyung Joon; Joo, Choun Ki

Abstract

PURPOSE
To describe the clinical phenotype of congenital cataract in Korean families and to determine whether the cataract is causally related to other congenital cataract with known gene. METHODS: We examined total 21 patients with congenital cataract and their families. Peripheral blood samples were obtained from congenital cataract patients and their families who visited clinics. The phenotypes were characterized by slit lamp examination and photographs of digital camera. And genetic traits were discriminated by family pedigree analysis. And we performed known mutation specific enzyme digestion, cold - SSCP and sequencing analysis for identification of genetic defects. RESULTS: We found nuclear (42.8%), anterior polar (4.8%), cortical (4.8%), sutural (4.8%) cataract. And the families affected with coexisting cortical and posterior polar opacity, posterior polar and post-subcapsular opacity were two cases (9.4%) respectively. We identified and examined a three-generation family affected with coexisting autosomal dominant zonular cataract and sutural opacity (CCZS, 4.8%: Family Yun). Previously the CCZS had mapped to chromosome 17q11-q12 and reported mutation of the beta A3A1-crystallin (CRYBA1) gene. We had not identified any mutation in CRYAB1 gene. CONCLUSIONS: In conclusion, we reported that nuclear type is very frequent in Korean patients with congenital cataract. And we had not identified any defects in CRYAB1 gene. These results demonstrated another gene caused this congenital cataract with same phenotype. Furthermore it will be necessary to perform the linkage analysis with microsatellite marker.