Abstract
Purpose: :
To investigate the genetic basis of the congenital cataract, we were screened mutations of four causative genes, the paired box gene 6 (PAX6), Heat-shock transcription factors 4 (HSF4), Major intrinsic protein (MIP), Gamma-crystallin D (CRYGD), in Korean patients with congenital cataract
Methods: :
Genomic DNA was extracted from blood samples of 97 patients of 43 families with congenital cataract visited the Department of Ophthalmology at the Seoul St. Mary’s Hospital. To screen of genetic variation, all exons of PAX6, HSF4, MIP and GRYGD genes were performed using polymerase chain reaction and direct sequencing. Control individuals were selected from the general population without cataract
Results: :
We screened two transcription factor genes (PAX6, HSF4), one crystalline gene (CRYGD) and one major intrinsic protein of lens fiber (MIP). In PAX 6 gene, we found six nonsynonymous mutations and one synonymous in exon 6 and four intragenic mutations. Among them, three nonsynonymous mutations, P69T, G100E, C112Y, and one synonymous mutation, P68P, were detected in one large family (CC_Y family). Other mutations, W100R, L106S and G110R, were detected three families, respectively. In HSF4 gene, a novel mutation, EX4+40G>A, was identified in CC_Y family, which results in substitution of a alanine residue by threonine at codon 40 (A40T). And D370E and H373D mutations were also detected in one family (CC_P). Two intragenic mutation, IVS3-17g>a and IVS6+98c>a, were detected in two families. From mutation screening of MIP, we detected two synonymous mutations in three families. In CRYGD, R140Q mutation was detected in one family. And also we detected two non-exonic mutations, IVS1-7c>g and 3UTR+12t>c, and two synonymous mutations (Y17Y and R95R). These mutations were not found in control individuals
Conclusions: :
The findings in the present study suggest that PAX6, HSF4 and CRYGD mutations are a genetic susceptibility factor for the development of Korean patients with congenital cataract.
Keywords: gene screening • candidate gene analysis • cataract