一仅有男性患者的leber遗传性视神经病变家系分子生物学分析

发布时间：2018-03-09 15:44

本文选题：Leber遗传性视神经病变　切入点：线粒体DNA　出处：《郑州大学》2010年硕士论文　论文类型：学位论文

【摘要】： 目的分析一未携带原发突变且仅有男性患者的Leber遗传性视神经病变家系的临床表型、遗传特征,检测其突变基因,探讨是否与x染色体有关。方法收集河南安阳一仅有男性患者且临床诊断为LHON家系的临床资料,分析遗传特征；用Primer5设计线粒体引物,PCR (polymerase chain reaction)-测序重新检测该家系是否携带3个原发突变。对先证者线粒体基因(mitochondrial DNA, mtDNA)全测序,将测序结果与修正的mtDNA剑桥标准序列比对,确定该家系的突变位点,然后在专业遗传学网站上查找这些突变位点的相关信息,必要时进行对照人群mtDNA测序分析,以确定致病突变；在ABI PRISM(?) Linkage Mapping Set Version 2.5试剂盒中挑选可以覆盖整条X染色体的18个微卫星荧光标记对家系内成员进行X染色体扫描,Genotyper3.7软件进行基因分型,Linkage和Merlin 1.1.2软件进行连锁分析,初步定位可能存在X连锁修饰基因的区域,进一步进行精细扫描和定位,最后利用Cyrillie软件构建单倍体型图,确定是否存在X染色体连锁修饰基因。结果此家系符合母系遗传特征,30位母系成员中6人发病,且全部为男性,表现出低外显率和男性患病偏倚的特点。重新测序发现该家系未携带3个原发突变。先证者mtDNA全测序结果发现31个同质突变位点,其中包括1个已报道的致病突变位点G3635A和2个未报道过的突变点ND4 T11809C与ND5A12340G。T11809C为无义突变,A12340G为错义突变,剩余28个突变点均为已报道过的线粒体多态,该先证者属于线粒体单倍体型F1。MtDNA测序所有其它母系成员均同时携带G3635A和A12340G突变。107位正常家系外对照中不存在G3635A和A12340G突变。连锁分析在DXS1060得到最大两点LOD值1.46(θ=0.0),但是两点非参数分析和多点非参数分析结果显示所有标记p0.05,单倍体型分析图未发现共分离单倍体。结论此家系为携带G3635A和A12340G突变的LHON家系；此家系不存在X连锁修饰基因。
[Abstract]:Objective to analyze the clinical phenotype and genetic characteristics of a family with Leber hereditary optic neuropathy without primary mutation and only male patients, to detect the mutation gene and to explore whether it is related to the x chromosome. Methods the clinical data of male patients with LHON were collected and the genetic characteristics were analyzed. Polymerase chain reaction- sequencing was used to detect whether the family carried three primary mutations. The mitochondrial DNA (mtDNA) of the proband was sequenced, and the results were compared with the modified mtDNA Cambridge standard sequence. Identify the mutation sites of the family, then search the website of professional genetics for the relevant information of these mutation sites and, if necessary, carry out the mtDNA sequencing analysis in the control population to determine the pathogenic mutation. Linkage Mapping Set Version 2.5 kit selected 18 microsatellite fluorescent markers that could cover the entire X chromosome. Genotyper3.7 software was used to carry out genotyping and Linkage and Merlin 1.1.2 for linkage analysis. The region of X linkage modifier gene may be located preliminarily, and further fine scanning and localization are carried out. Finally, haploid pattern is constructed by Cyrillie software to determine the existence of X chromosome linkage modification gene. Results 6 of the 30 maternal members of this family, all of whom were male, were in accordance with the maternal genetic characteristics. It was found that the pedigree did not carry three primary mutations, while the proband mtDNA sequencing revealed 31 homogenous mutation sites. Among them, one reported mutation site G3635A and two unreported mutation sites ND4 T11809C and ND5A12340G.T11809C were nonsense mutations and A12340G were missense mutations. The remaining 28 mutation sites were all reported mitochondrial polymorphisms. The proband belonged to mitochondrial haploid type F1. MtDNA sequencing. All other maternal members were carrying G3635A and A12340G mutations simultaneously. There were no G3635A and A12340G mutations in the normal pedigree. Linkage analysis showed that the maximum two LOD values were 1.46 (胃 0.00. 01) in DXS1060, but G3635A and A12340G mutations were not present in the normal pedigree. The results of two-point nonparametric analysis and multi-point nonparametric analysis showed that all markers were p0.05, and no cosegregated haploid was found in haploid pattern. Conclusion this family is a LHON family with G3635A and A12340G mutations, and there is no X linkage modifier gene in this family.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2010
【分类号】：R774.6

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