Mutation Maps Drawing And Analysis Of Common Deafness Genes Among Non-syndromic Hearing Loss In Northwest China

Hearing plays an irreplaceable important role in social activities in human daily life. Auditory dysfunction, one of the humanity's greatest suffering and manifested as varying degrees of hearing loss, which is the common disease leading to speech communication barriers.It was found that many known or unknown genetic environmental causes or a combination thereof may cause deafness, at least 50% of which caused only by heredity. However, with the identification of 140 loci for deafness, recent findings indicate that a small number of genes cause a large proportion of genetic hearing loss. The five provinces or autonomous regions in the Silk Road of China contain a large district, with inconsistent distribution of population or nation and relatively backward economy and culture now. Based on the samples from Gansu, Qinghai and Xinjiang collected from the year 2004 to 2009 and with the further research to deaf people from Shaanxi and Ningxia. This study focused on analyzing some common deafness genes in Northwest Chinese deaf population to investigate the molecular pathogenesis and molecular epidemiology, with supplements to gene diagnosis and genetic counseling and provide the basis for the government to develop prevention policies and systems for hearing loss.Chapter I:Mutation maps drawing and analysis of mitochondrial DNA 12SrRNA m.1555A>G mutation among non-syndromic hearing loss in Northwest China and exploring analysis of new mutationsThe aim of the present study was to draw mitochondrial DNA12SrRNA m.1555A>G mutation map in a total of 2398 cases of non-syndromic deaf patient representative of the general population of the Shaanxi, Gansu, Qinghai, Ningxia and Xinjiang along the Silk Road.The carrier frequency of mitochondrial DNA 12SrRNA m.1555A>G mutation was estimated to be 5.25%(126/2398) in the studied population.In the 126 m.1555A>G homogeneity mutation carriers, and one heterogeneity carrier,52 cases were found to have a clear history of using aminoglycoside antibiotics, the results suggested that the application of aminoglycoside antibiotics in this region, was an important reason of higher incidence of m.1555A>G mutation in deaf-mute population. Statistically significant difference was showed between different districts or different nations. Simultaneously, the relationship between the 26 discovered nucleotide changes including the m.1556C>T and deafness still needs more deep research.Chapterâ…¡:Mutation maps drawing and analysis of GJB2 gene mutation among non-syndromic hearing loss in Northwest China and correlation analysis of special mutationsBased on the research of Chapterâ… ,the aim of the present study was to draw the map of GJB2 gene mutation in 2398 cases of non-syndromic deaf patient representative of the general population of the Shaanxi, Gansu, Qinghai, Ningxia and Xinjiang along the Silk Road. As a result,245 cases were caused by mutations of GJB2 gene, gave a rate of 10.2%(245/2398). The statistical analysis showed that the GJB2 gene mutations carrier rate was in different districts or nations.The hot spot mutations were also different in four main nations:Han, Hui, Uighur or Tibetan. c.235delC was the hot spot mutation among these four nations, but in different rate: the highest rate in Han, with a rate of 10.4%(362/3618), while the lowest in Tibetan. The mutation c.35delG, very popular in Caucasian, also found in three main nations (Han, Hui and Uighur), with the highest carrying rate of 2.9%(12/414) in Uighur compared to the lowest rate of 0.3%(10/3618) in Han.This study also found the dominant GJB2 gene mutations in three families. Finally, corrected the name of a mutation, further enriched the content of GJB2 gene mutations.