靶向捕获二代测序检测不明原因儿童失神癫痫的致病基因分析

发布时间：2018-06-18 23:26

本文选题：儿童失神癫痫 + SCN1A　；参考：《山西医科大学》2017年硕士论文

【摘要】：目的:儿童失神癫痫(Childhood Absence Epilepsy,CAE)是一种常见的遗传性全面性癫痫,研究表明半数以上儿童癫痫与遗传因素相关,目前,虽报道了一系列与儿童失神癫痫相关的基因,但其发病原因和致病机制尚不明确。本研究通过靶向捕获二代测序技术对100例儿童失神癫痫患儿进行测序,以期发现新的易感基因及致病性突变,为探讨儿童失神癫痫的致病机制提供依据,并有利于了解其他类型遗传性全面性癫痫综合征可能的发病机制。此外,对遗传性癫痫的临床诊治、遗传咨询及基础研究也具有积极意义。方法:选取从北京大学第一医院神经科门诊收集的100例不明原因CAE患儿临床资料和外周血标本,应用靶向捕获二代测序对其进行511个癫痫相关基因的突变筛查,筛选出可能的致病突变。然后,应用一代测序(Sanger测序法)验证突变的父母来源,结合生物学、基因学及临床表现明确其致病性,对氨基酸序列进行保守性分析,得出致病性突变。结果:本研究在100例儿童失神癫痫患儿中共发现1131个基因变异,最终从3例CAE患儿中发现3个变异为致病性突变,分别为SCN1A(c.5,399TA)、SCN8A(c.2,371GT)和CLCN2(c.481GA),均为新生突变(de novo),Polyphen2软件对3个突变蛋白的功能预测为很可能致病(probably damaged);从1例CAE患儿中发现2个变异GPR98(c.5815GA和c.16252GT),基因变异分别来自母亲和父亲,Polyphen2软件对前者变异蛋白的功能预测为很可能致病(probably damaged),对后者的功能预测为良性(benign)。根据人类基因突变数据库(Human Gene Mutation Database,HGMD),这5个突变均位于高度保守区域,均为未报道的突变(novel mutation)。结论:SCN1A、SCN8A、CLCN2和GPR98可能是儿童失神癫痫的易感基因。我们的发现不仅扩展了SCN1A、SCN8A、CLCN2以及GPR98的疾病谱,而且发现了可能致病的儿童失神癫痫易感基因。
[Abstract]:Objective: childhood Absence EpilepsyCae) is a common type of hereditary comprehensive epilepsy. Studies have shown that more than half of children with epilepsy are related to genetic factors. At present, a series of genes related to childhood aphasia epilepsy have been reported. However, the causes and pathogenesis of the disease are still unclear. In this study, 100 children with aphasia were sequenced by targeting capture second-generation sequencing technique, in order to find new susceptible genes and pathogenicity mutations, and to provide evidence for exploring the pathogenic mechanism of childhood aphasia. It is helpful to understand the possible pathogenesis of other types of hereditary comprehensive epilepsy syndrome. In addition, the clinical diagnosis and treatment of hereditary epilepsy, genetic counseling and basic research are also of positive significance. Methods: the clinical data and peripheral blood samples of 100 children with CAE of unknown origin were collected from the Department of Neurology, first Hospital of Peking University, and 511 epileptic-related gene mutations were screened by target capture second generation sequencing. A possible pathogenic mutation was screened out. Then, the parental origin of the mutation was verified by Sanger sequencing method. The pathogenicity of the mutation was confirmed by biological, genetic and clinical manifestations. The amino acid sequence was conservatively analyzed and the pathogenicity mutation was obtained. Results: in this study, 1131 gene mutations were found in 100 children with aphasic epilepsy, and 3 mutations were found as pathogenicity mutations in 3 children. SCN1AU c. 5399TAA (SCN8An c. 2371GTT) and CLCN2C. 481GAA, respectively. The function of the new mutation de novophin Polyphen2 software predicted that the three mutant proteins were likely to be possibly damaged.Two mutations of GPR98 c. 5815GA and c. 16252 GTN were found in a case of CAE, and the genetic variation was derived from mother and father Polyphen2 software respectively. The function of mutant protein was predicted to be probably probable and the function of the latter to be benign. According to the human gene mutation database, Human Gene mutation Database (HGMDA), the five mutations are all located in highly conserved regions, all of which are novel mutation. Conclusion the two genes, CLCN2 and GPR98, may be susceptible to aphasia in children. Our findings not only extend the disease spectrum of SCN1A, SCN8, CLCN2 and GPR98, but also reveal the susceptibility gene to epilepsy in children with possible pathogenicity.
【学位授予单位】：山西医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R742.1

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