[Analysis on mutations of GJB2 gene in Chinese population]

To determine the prevalence and types of GJB2 mutations and to investigate the genetic mechanism in Chinese autosomal recessive deafness.

The subjects were four Chinese pedigrees (39 individuals) and 50 normal adults. GJB2 was amplified by PCR. The products were digested with restriction enzyme Apa I, then sequenced.

Homozygous deletion C at position 232-235 of GJB2 (235delC),which resulted in frameshift mutation, was found in four affected individuals of two pedigrees; the compound heterozygous deletions (235delC/232G to A) were found in two affected individuals in one pedigree. One carrier with 235delC was found in normal controls (1% allele). Two kinds of polymorphisms 79G to A(V27I) and 3 41A to G(E114G) were found in both affected and normal controls. The frequencies of allele for 79G to A and 341A to G in normal controls were 30%, 21%, respectively.

235delC mutation of GJB2 was related with Chinese autosomal recessive deafness, and the 232G to A(Ala78Thr) missense mutation was found to be a novel mutation.