Molecular Epidemiology Investigation Of Common Deafness Genes In Deafness Patients Of Different Ethnic Origins In Northwest China

Deafness is one of significant diseases of mankind,which is the cause of speech impediments communictation.Approximately one in 1000 children is affected by severe or profound hearing loss at birth or during early childhood.Genetic deafness is highly genetic heterogeneity,and the rate of mutation frequency of the deafness gene is great difference in different area and crowd.In deafness genes cloned,GJB2, SLC26A4,DNA12SrRNA,TMC1 and POU3F4 have the high mutation frequency in population from different ethnic origns.In recent years,the research about the prevevlance of these common deafness genes in Chinese population had the progress and the discovery,but these studies were mainly made in the Chinese Han population,and molecular epidemiology research about the deafness gene in Chinese Minority Groups are relatively few.So we study the prevelance of these common deafness genes mutations in the patients in northwest China where many Minority Groups are living in.This thesis comprised two parts and the details were described as following.The first part:Molecular epidemiological study of GJB2 mutations in deafness patients from Minority Groups and Han ethnic origin in northwest China.This sdudy was to investigate the prevalance and characteristics of GJB2 mutations in 559 sporadic patients with sensorineural hearing loss(SNHL) from Uigur,Hui,Mongolian and Han nationality in northwest China.GJB2 mutations were detected in four nationalities,and there was a rather high mutation rate of GJB2 in Uigur,Hui,Mongolian and Han SNHL patients.235delC and 299-300delAT were detected in the patients of the four groups,235de1C was the most common mutation in every groups.The highest carrier frequency of 235delC is 15.2%in Han deaf-mute students,and the lowest is 3.8%in Mongolian patients.235delC and 35delG mutations were found in Uigur deaf-mute students,and the carrier frequency of 235delC and 35delG mutations is 7.1%and 5.2%respectivley.Two novel mutions were found in Uigur patients.Two patients with 35delG mutation were found in Hui deaf-mute students.The characteristics of GJB2 mutations of Hui and Mongolian patients were basically consistent with one of Han group.The second part:Molecular epidemiological study of SLC26A4 and mtDNA12SrRNAA1555G mutations in deaf-mute students from different ethnic orign in Xinjiang Uigur Automonous Region of ChinaThis study was to determine the prevalance and characteristics of SLC26A4 and mitochondrial DNA(mtDNA) A1555G mutations in 402 patients with sensorineural hearing loss(SNHL) from Xinjiang Uigur Automonous Region,China. The homoplasmic mtDNA A1555G mutation was found in Han and Uigur deaf-mute students,and the carrier frequency of A1555G was 3.8%and 1.4%,respectively. The IVS7-2A＞G mutation of SLC26A4 were detected in Han and Uigur patients,the carrier frequency of IVS7-2A＞G was 9.5%and 0.9%,respectively.IVS7-2A＞G was the common mutation of SLC26A4 in Han patients,and the hot mutation of SLC26A4 was different between Han and Uigur deaf-mute students.More comprehensive examination of SLC26A4 mutations were needed to undergo in Uigur patiens,and the muatations of deafness gene were detected in more samples from other nationalities in order to determine the characteristic of the molecular epidemiology of deafness genes in northwest China.