Characteristic Analysis of Frequent Deafness-correlative Genes Mutation in Hui Nationality Patients with Non-syndromic Hearing Loss from Northwest China
|Keywords||Hui ethnic group Non-syndromic hearing loss Drug-induced deafness Mitochondrial DNA GJB2gene SLC26A4gene Gene mutation Clinicalepidemiolog|
Deafness, seriously affects the quality of population, is the most significant cause of linguistic barrier, the causes of which including inherit(60-80%) and environmental factors. Nonsyndromic sensorineural hearing loss(NSHL) accounts for70%in inherit factors.To date, there are more than140genes related hearing loss, mitochondria DNA12Sr RNA1555A>G, GJB2and SLC26A4gene are the most common deafness-related-genes of NSHL. Lots of studies proved that the mutation frequency and mutation pattern are disparate in different areas and races. Hui, the descendant of the Arabs, was a special nationality in China after constantly evolution, migration and fusion with other nationalities in history. Total of Hui ethnic group population is more than ten million in China, more than half of which live in Northwest China. So far, there was no detailed research report about Hui ethnic group, in this study we collected420Hui NSHL patients to discuss the hot-spot mutation, frequency and the relation-ship betweem characteristic of genes mutation and origin of the hui nationality,the results of which will provides the epidemiology basis on molecular etiology and genetic counseling for this population, at the same time, provides scientifice evidence for the government in order to draw up strategy in the work of prevention and treatment for deafness in different races and areas.The aim of this study is to analysis the characteristic of m.1555A>G, GJB2and SLC26A4genes mutation in Hui patients with non-syndromic hearing loss in Northwest China(Gansu, Ningxia, Qinghai, Xinjiang and Shaanxi), probing into the frequency and hotspot mutation types of three frequent deafness-correlative genes.Because m.1555A>G mutation is the molecular etiology of aminoglycoside antibiotic-induced deafness(AAID), we analysis the clinical etiology of all patients, the results showed that285(67.86%) patients are congenital deafness, in which40(9.52%)patients had a family history;108(108/420) had the history of prescribing drugs,in addition,91(84.26%) of these objects had a history of using aminoglycoside antibiotic(AmAn) Moreover,27patients were caused by other etiologies. Thus, it can be seen that congenital deafness(including Hereditary hearing loss) and hearing loss induced by drugs are the most common factors. Genetic testing showed that11(2.62%) cases were caused by m.1555A>G homozygous mutation in420patients with NSHL,6of whom had a specific history of AmAn(6/11=54.55%), and one case was doubtful. Therefore, there has a great significance of m.1555A>G gene screening in order to prevent the deafness occurring in Hui population in Northwest China.At the same time,we analysis the characteristic of GJB2and SLC26A4genes mutation in420Hui ethnic group patients with NSHL and draw the map of GJB2gene mutation investigate the mutation frequency and forms of two genes. Amplified the target gene by polymerase chain reaction (PCR) after extracting genomic DNA from whole blood, then direct sequencing was used to the coding region of GJB2gene,exon8and19of SLC26A4gene. Results showed that41(9.76%) cases,including homozygote and compound heterozygote,were caused by GJB2gene mutation, which was the most frequent deafness-related gene.The allel frequency of c.235delC accounts for6.90%,as well as the most frequent(51.33%) mutational pattern in GJB2gene.20patients(4.76%) were found carring two allel mutations in SLC26A4gene.The allel frequency of c.919-2A>G is5.0%,accounts for a total of68.85%in all base alterations of SLC26A4gene,is the major mutant form of SLC26A4gene.Through this study we can provide the molecular epidemiology basis for Hui ethnic group patients with NSHL from Northwest China in genetic diagnosis, genetic counseling and therapy by associated testing of the involved three genes.