[Features of nationwide distribution and frequency of a common gap junction beta-2 gene mutation in China].
OBJECTIVE
To determine the prevalence of a common GJB2 mutation in a big Chinese population of deaf children and the features of its distribution in regions all over the nation and to provide epidemiology data and expertise for genetic testing of deafness in China.


METHODS
The DNA samples of NSHI patients and normal controls were collected from different typical areas of China. The method of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) with ApaI was used to determine the genotype of GJB2 235 site.


RESULTS
Totally 16.3% of patients carried at least one 235 delC mutant allele. Among them, 7.8% was homozygous and 8.5% was heterozygous. The prevalence of GJB2 235delC mutation in China was evident, and the significant difference of 235delC mutation frequency was found in sub-population from different areas and different ethnic groups.


CONCLUSIONS
Based upon the result of this screening as stated, Chinese NSHI patients appear to have 235delC frequency and the number of GJB2 related deafness was estimated to be huge. The testing of GJB2 235delC mutation would play an important role in genetic diagnosis and screening in China. As high as 15% of patients could be diagnosed as GJB2 caused deafness (bi-allelic mutation) only by means of this simple, fast and economic assay. In addition, patients were negative for 235delC mutation would be candidates for further mutational analysis of GJB2 or other deafness related genes.
Dai
Pu
P
Department of Otorhinolaryngology Head and Neck Surgery, General Hospital of Chinese People's Liberation Army, Beijing 100853, China.
Yu
Fei
F
Han
Bing
B
Wu
Hao
H
Yuan
Yong-Yi
YY
Li
Qi
Q
Wang
Guo-Jian
GJ
Liu
Xin
X
He
Jia
J
Huang
De-Liang
DL
Kang
Dong-Yang
DY
Zhang
Xin
X
Yuan
Hui-Jun
HJ
Leejun
C Wong
CW
Han
Dong-Yi
DY
D000293:Adolescent; D000328:Adult; D000483:Alleles; D044466:Asian People / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D000072259:Connexin 26; D017630:Connexins / Q000235:genetics*; D005260:Female; D005838:Genotype; D006319:Hearing Loss, Sensorineural / Q000453:epidemiology / Q000235:genetics*; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D008297:Male; D017354:Point Mutation; D015995:Prevalence; D055815:Young Adult
D017630:Connexins; C000607042:GJB2 protein, human; D000072259:Connexin 26