The Study Of The Deafness Gene GJB2 Mutation In A Hereditary Nonsyndromic Deaf Families

[Objective] To determine the mutation situs, frenquence and form in a hereditary nonsyndromic deaf families, and to contrast the difference of the mutation situs, frequency and form between hearing loss and normal persons in the families and non-families.[Methods] There are thirty-four persons collected in three generations of this genealogy, and six persons of them were deafness. All patients with deafness were binaural prelingual, sensory and nervous deafness, and without other systems abnormity. This genealogy is considered as study group. Twenty persons with sporadic congenital deafness and twenty-two normal persons are considered as control group. The DNA of simples were abstracted, and also inspected the mutation of deafness gene GJB2 with PCR-Squencing method in the study and control groups.[Result] We found one nucleotide change in GJB2 genes, that was 636delA, however, the change of 636delA resulted in the change of protein expression, and we found 636delA (p<0.05) had high mutation rate in hereditary nonsyndramic hearing loss, and we also noticed that the homozygosity mutation of 636delA (p<0. 05) had high mutation rate in hearing loss of the families after we analysed them.[Conclusion] By analyzing of them, we found 636delA of the GJB2 resulted in the change of protein expression, that was Leu lying in the 212^th was changed into Cys, which resulted in frame—shift mutation. 636delA of the GJB2 had high mutation rate in hereditary nonsyndramic hearing loss, so we considered that the 636delA mutation was significantly related with hereditary nonsyndramic hearing loss. And we considered the homozygosity mutation of 636delA was probably important gene to the deafness in the deaf families too.