Analysis on mutations of GJB2 gene in Chinese population

Objective To determine the prevalence and types o f GJB2 mutat ions and to investigate the genetic mechanism in Chinese autosomal recessive dea fness. Methods The subjects were four Chinese pedigrees (39 i ndividuals) and 50 normal adults. GJB2 was amplified by PCR. The products were digested with res triction enzyme ApaⅠ, then sequenced. Results Homozygous dele tion C at positi on 232-235 of GJB2 (235delC),which resulted in frameshift muta tion, was found in four affected individuals of two pedigrees; the compound hete rozygous deletions (235delC/232G→A) were found in two affected individuals in one pedigree. One c arrier with 235delC was fou nd in normal controls (1% allele). Two kinds of polymorphisms 79G→A(V27I) and 3 41A→G(E114G) were found in both affected and normal controls. The frequencie s of allele for 79G→A and 341A→G in normal controls were 30%,21%, respectivel y. Conclusion 235delC mutation of GJB2 was related with Chinese autosoma l recessive deafness, and the 232G→A(Ala78Thr) missense mutation was found to b e a novel mutation.