[An investigation of SLC26A4 gene mutation in nonsydromic hearing impairment in Hunan province of China].

To determinate the occurring frequency and mutational hot spot in Hunan province.Blood samples was obtained from 96 patients with nonsydromic hearing impairment in Hunan province. PCR and DHPLC techniques were used to screening for all the 21exon of SLC26A4. PCR samples which were abnormal for DHPLC screening were analyzed with direct sequencing. Sequencing results were analyzed in DNASTAR software.Fifteen of 96 patients were found to have SLC26A4 gene mutations, detection rate was 15 6 , for 3 examples were homozygous mutations, ten samples were complex heterozygous mutations and 2 were heterozygous mutations. Totally, sixteen base variations were found, including 10 types of known gene mutation were identified (S90L, S252P, IVS7-2A>G, T410M, N392Y, IVS10-12T>A, S448X, G497S, S517fs, H723R. Four types of novel gene mutation (S8X, A227P,C565fs, Y728H), one type of same sense mutation (c. 2182 T>C)and 1 type of polypeptide IVS11+47 T>C). IVS7-2A>G was the most common gene mutation , which 9 samples were identified with, and it's detection rate was 9.38% and 5.73% for all the mutant alleles. IVS11+47 T>C was the most common polypeptide, which 20 samples were detected.IVS7-2A>G was the most common gene mutation type for nonsyndromic hearing impairment in Hunan province; 4 novel mutations which were detected in the study enriched SLC26A4 gene mutation spectrum of Chinese.