| Deafness, also known aS hearing impairment,me,alls that the ability people feel the size of the voices and distinguish the voice is below normal. Hearing loss has a high proportion in the physical disabilities,which has serious impact on people's normal life. GJB2 is responsible for up to 21% of cases of deafness in the Chinese population. The most common mutation is a frameshift mutation due to deletion of a single cytosine at position 235 (235delC). Our study focused on the NSHI population in Shandong province, especially in Dongying and Liaocheng and make the research in order to figure out the relation between deafness and mutations of GJB2 gene.Part one:collection of clinical data and mutations screening of the GJB2 235delC in NSHI cases in parts of Shandong ProvinceObjective:To explore the frequency of GJB2 235delC mutation and the audiological phenotypic characteristics in 252 nonsyndromic hearing impairment (NSHI) patients and in 208 controls in Shandong province,as well as the genetic analysis of several typical pedigrees among the patients.Methods:We collected 64 NSHI cases in Special schools, Rehabilitation center for deaf children from Dongying and Liaocheng, department of Otolaryngology of Qilu hospital.And we gathered and detailed clinical information at the same time.Results:1.The study results indicated that the 235delC is the most common mutation in these populations. The general rate of mutation is 21.04% while the general rate of mutation is 17.31% in the healthy volunteers with the clear family history.The general rates of mutation of GJB2 235de1C in experimental group and control group are significantly different (P=0.001).2. The gene frequency of GJB2 235delC is 17.06% in the patients while it is 9.13% in the healthy volunteers with the clear family history.And there is no significantly different between theexperimental group and control group (P=0.650).3.235delC detectable differences between different regions of Shandong Province: Specimen source area and 235delC detectable differences between regions of statistics These 252 cases of NSHI patients in Shandong Province are mainly from Dongying, Liaocheng, Jinan and other regions,The statistical analysis of mutation rates of GJB2 235delC among different regions:P=0.037 (P< 0.05) between Dongying and Liaocheng; P=0.635 (P> 0.050) between Dongying and Jinan; P=0.823 (P>0.050) between Dongying city and other regions; P=0.502 (P>0.050) between Dongying and Shandong Province aggregate; P=0.030 (P< 0.05) between Liaocheng and jinan; P=0.053 (P> 0.050) between Liaocheng and other cities; P=0.072 (P> 0.050) between Liaocheng and Shandong Province aggregate; P=0.829 (P>0.050) between Jinan and other cities; P=0.313 (P> 0.050)between Jinan and Shandong Province aggregate. The gene mutation rate frequency of 235delC mutation in NSHI patients of Liaocheng city is significantly lower than that of Dongying and Jinan, and no obvious difference with other regions in Shandong Province.Conclusions:Testing for the GJB2 235delC mutation explained deafness in 21.04% of Shandong GJB2 monoallelic patients.Part two:NSHI is associated with the GJB2 gene pathogenic mutations in several pedigreesObjective:To analysis the genetic characteristics of GJB2 235delC of several typical pedigrees among the NSHI patients.Methods:We reported here the characterization of these pedigrees carrying 235delC mutations in GJB2 gene. Clinical presentation showed the variable phenotypes including bilateral, severity,and audiometric configuration. We found that all probands have one homogenrous or compound heterogeneous pathogenic mutations in GJB2 gene, and his or her parents just have one corresponding heterogeneous.Results:The 235delC of GJB2 gene is the most common type of deafness-causing mutation in the patients with congenital hearing loss.Conclusions:The data will provide basis for antepartum screening and antenatal diagnosis, making sure that the child with the same genotype will not appear again, the hearing loss will not happen in this family. |
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