【作者】 赵杰；

【导师】 许安廷；

【作者基本信息】 山东大学 ， 耳鼻咽喉科学， 2011， 硕士

【摘要】 耳聋,即听力障碍,是指人们对声音的大小及辨识度下降的表现。听力障碍在各种身体残疾中所占比例较高,严重影响患者的日常生活。在遗传性非综合征耳聋患者中,约有21%是由GJB2基因突变引起的,而其中最常见的是235位点一个胞嘧啶缺失(235delC)所致框移突变造成的。本实验针对山东省内,主要是东营、聊城、济南地区收集病例,进行GJB2 235delC突变的流行病学调查。第一部分山东省内部分地区遗传性非综合征型耳聋患者临床资料的收集与GJB2 235delC突变的筛查目的：探讨山东省内先天性非综合征型聋(NSHI)患者的GJB2 235delC突变频率和听力学表型特点,并进行几个典型家系的遗传分析。方法：以完全自愿为原则,收集前来山东大学齐鲁医院耳鼻喉门诊及病房的本省NSHI患者及济南市、东营市、聊城市及其他地区聋儿康复机构与特殊教育学校符合条件的非综合征耳聋患者共252例作为实验组,其直系家属作为有明确家族史但听力表型正常且无全身系统疾病的健康志愿者208例作为对照组,提取外周血DNA进行GJB2基因聚合酶链反应(PCR)扩增,使用耳聋基因GJB2 235delC检测试剂盒标记PCR产物进行荧光检测,依据DNA扩增的荧光曲线模式分析是否存在GJB2基因235delC位点纯合或杂合突变,并对检测结果进行汇总,利用统计学方法进行分析,同时选取几个典型家系进行遗传分析。结果：1.GJB2 235delC突变检出率：在实验组252例NSHI患者GJB2 235delC突变总检出率21.04%,对照组208总检出率17.31%。实验组与对照组基因型构成比之间做卡方检验,p=0.001,两组间基因型构成比差异具有统计学意义。2. GJB2 235delC等位基因频率：实验组等位基因频率17.06%(86/504),对照组等位基因频率9.13%(38/416),两组之间235delC等位基因频率(17.06%和9.13%)做卡方检验,p=0.650(P>0.050)无统计学意义。3.标本来源地区及地区间235delC检出率差异的统计本实验中252例NSHI患者来自山东省内各地,主要来自东营、聊城、济南及其他各地区,用多个样本率的卡方检验进行235delC检出率分布差异的统计学分析：东营与聊城P=0.037 (P<0.05);东营与济南P=0.635 (P>0.050);东营与省内其他地市P=0.823 (P>0.050);东营与山东省平均水平P=0.502 (P>0.050);聊城与济南P=0.030 (P<0.05);聊城与其他地市P=0.053 (P>0.050);聊城与山东省平均水平P=0.072 (P>0.050);济南与其他地市P=0.829 (P>0.050);济南与山东省P=0.313 (P>0.050);其他地市与平均水平P=0.462 (P>0.050)。即聊城市NSHI患者GJB2 235delC突变率明显低于东营市及济南市,而与其他地区无明显差异,山东省除聊城市NSHI患者235delC突变率较低外,其余并无明显地域差异。结论：山东省内遗传性非综合征型耳聋患者中GJB2基因235delC突变检出率为21.04%,各地市除聊城市此基因突变检出率较低(12.36%),明显低于东营市及济南市,山东省内并无明显地域差异,等位基因频率为17.06%,具有明确家族史的健康志愿者中GJB2基因235delC突变检出率为17.31%,等位基因频率为9.13%。无论是在患者还是在有明确家族史的健康志愿者中,GJB2 235delC突变率均处于较高水平。第二部分携带GJB2基因235delC突变的4个耳聋家系的遗传特点分析目的：对山东省内先天性非综合征型聋(NSHI)患者的GJB2 235delC基因突变检测结果汇总后,选取其中典型的4个家系进行遗传分析,探讨此位点突变与NSHI的关系。方法：本次实验所入选患者家庭成员进行全面的信息采集及体格检查,并进行纯音测听,同时检测是否携带235delC突变,选取几个典型家系画家系图进行遗传分析。结果：此次实验中所选GJB2 235delC家系临床资料汇总如下表所示：结论：GJB2基因为常染色隐性遗传,单纯的235 delC杂合突变并不会导致耳聋,但本次实验中仅进行这一个位点的检测,因此并不能单纯以此结果来判定。当复合病理性突变存在时,则可导致重度或极重度的感音神经性聋。更多还原

【Abstract】 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.更多还原