The Analysis Of The Molecular Epidemiology In The Inhereditary Pedigrees In Northwest Of China

Inhereditary hearing impairment was a single gene disorder which was thought to be the perfect sample to be studied.With the development of the Human Genome Program and the genetic code of the deafness related gene being broken,the otologist,epidemiologist, geneticist and the molecular biologist studied the deafness gene in different ways,in order to find the pathogenic mechanism.Our group began to study the clinical and molecular epidemiology of deafnees in the northwest of China since 2004,and had made great progress.They made sure that the mutation of GJB2 gene;SLC26A4 gene and mtDNA 12SrRNA were the most prevalence pathogenicity gene in the sporadic patients in the northwest of China.This study is to analyze the molecular epidemiological feature of the common deafness gene by contrasting the mutation position and the frequencies of the GJB2 gene, mtDNA 12SrRNA A1555G and SLC26A4 gene between the patients from unrelated family and the cases with family history.The purpose is to identify the hot spots mutation and the distribution of this three gene mentioned above in the pedigrees,and to prepare for the other gene mutation detection or for the further screening,cloning and mapping of the candidate gene.Methods One hundred and seventy hearing impairment patients with family history were performed medical examination to exclude the syndromic hearing impairment and the impact of environment factors.The genomic DNA were extracted from the white blood cells(leucocytes).and the polymerase chain reaction were performed to amplified the whole coding areas of GJB2 gene and SLC26A4 gene,the position from 1226 to 1998 of the mtDNA 12SrRNA,.the products of PCR were sequenced and analyzed by software.Results Twenty four patients of pedigrees were detected the mutation of GJB2 gene,sixteen patients were detected the mutation of mtDNA12SrRNA A1555G,and fifteen had the SLC26A4 gene mutation.The mutation frequencies of GJB2 gene,mtDNA 12SrRNA and SLC26A4 gene were 14.8 percent,9.4 percent and 8.8 percent,respectively. The results of the three genes(GJB2 gene,mtDNA 12SrRNA and SLC26A4 gene)in the sporadic patients were one hundred and fifty nine,fifty one and one hundred and thirty nine respectively,so the corresponding mutation frequencies were 19.4 percent,6.4 persent and 17.0 percent,respecttively.Conclution GJB2 gene is the most common gene in the two groups,the mutative frequencies of GJB2 gene in the pedigrees or the sporadic patients had no significant deviation in these two groups,on the contrary the mutation frequencies of SLC26A4 and mtDNA12SrRN gene had significant difference.