[Restrictive fragment length polymorphism analysis of gamma-crystallin in congenital cataract families].

Using gamma-crystallin gene probe P5G1, we investigated the RFLP in two large families of congenital cataracts and normal people, calculated the allelic gene frequency and defined the haplotypes by genetic linkage analysis. In accordance with foreign reports, TaqI/p5G1 detected 3 polymorphic sites, and the allelic gene frequency was close to that in foreign reports. However, foreign reports claimed that the haplotype P was linked to Coppock cataracts, but we did not find such linkage by haplotype analysis. The result suggests that not all the inherited cataracts are linked to gamma-crystallin gene, and the haplotype P should not be simply regarded as genetic marker in prenatal diagnosis.