233～235delC mutation analysis of GJB2 gene in nonsyndromic hearing impairment patients from China / 中国耳鼻咽喉头颈外科

ABSTRACT

OBJECTIVE To determine the prevalence of the GJB2 233～235delC mutation in nonsyndromic hearing impairment(NSHI)patients from China. METHODS Subjects include 917 students randomly selected from the Deaf and Mute Schools of Guangdong, Guangxi, Henan, Hebei, Shanxi, Heilongjiang, Jilin and Inner Mongolia. Peripheral blood samples were obtained and DNA templates were extracted by extraction kits. Using polymerase chain reaction(PCR),the coding region of the GJB2 gene was amplified. Mutations were detected by restriction endonuclease. RESULTS 233～235delC was found in 156 cases (17.01 %). Sixty-nine cases(7.52 %)were homozygous and 87 cases(9.49 %)were heterozygous. The detection rate differs in the subjects from different regions: Inner Mongolia(25.18 %),Hebei (23.19 %),Jilin(18.97 %), Shanxi (18.08 %),Heilongjiang(17.78 %),Henan(15.09%), Guangdong(13.02 %),Guangxi(6.59 %).CONCLUSION The hot spot of GJB2 gene mutations in Chinese nonsyndromic hearing impairment patients is 233～235 delC. The incidence rate is 17.01 % and is different in different regions. All differences are statistically significant(x2 =17.998,P