一个导致家族性房间隔缺损的新的GATA4基因突变

发布时间：2018-03-11 10:51

本文选题：先天性心脏病　切入点：房间隔缺损　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：先天性心脏病是一种非常普遍的新生儿缺陷,具有很高的发病率和死亡率,发病率约为千分之八到十二[1]。房间隔缺损约占所有先天性心脏病的10%,占成人先天性心脏病的20%-30%[2]。从解剖学上讲,它是由于房间隔的缺损或者缺失,引起血液直接在心房间流通。目前,有超过10种编码转录因子或辅酶因子(NKX2.5,GATA4,TBX5,TBX20,and CITED2)、肌小节结构蛋白(ACTC1,MYH6,MYH7,and MYBPC3)、金属蛋白酶(TLL1)的基因被认为与遗传性房间隔缺损有关。其中,GATA4和NKX2.5是具有较高外显率的突变型[3,4]。由7个外显子组成的GATA4基因,编码了锌指结构转录因子GATA4,它存在于多个与心脏发育相关基因的启动子中[5]。据研究报道,在人类基因突变数据库中,有123个GATA4的变异型可以引起先天性心脏病,例如法洛四联症,房间隔缺损,室间隔缺损和扩张型心肌病。GATA4结合蛋白编码了一个锌指结构转录因子,它在胚胎形成和心脏生长过程中扮演了重要的角色。在本文中,我们通过对一个由4代人组成的中国家系的研究,发现了一个新的GATA4变异型(c.A899C,p.K300T),它出现在所有患病成员和两个不完全外显的携带者身上。该变异在对照组中没有发现,且没有文献报道,在人类单核苷酸变异数据库(db SNP)、基因组变异数据库(EVSD)及人类基因突变数据库(HGMD)中均没有记录。生物信息学软件(The polyphen2,SIFT and Mutation Taster)预测该变异型是有害的。从果蝇到人类,该变异型中的赖氨酸位点一直高度保守,并被认为是GATA4蛋白的甲基化位点。通过使老鼠的GATA4转录活性减弱,甲基化氨基酸已经被证实与心脏发育有关。我们的研究拓宽了GATA4基因的变异频谱,并首次报道了该GATA4变异型的甲基化位点与房间隔缺损相关。目的:寻找并确定一个跨越4代人、涉及68人的房间隔缺损家系的致病基因及其突变。方法:利用全外显子组测序与多重序列比对和生物信息学预测相结合的方法对该房间隔缺损家系进行遗传学分析。结果:1.在所有患病家族成员(II:6,III:4,III:5,III:11,III:26,III:31,IV:1,IV:4)及两个未患病携带者(II:10,III:1)的GATA4基因4号外显子上,发现了一个新的非同义突变的变异型(c.A899C,p.K300T)。它在db SNP,EVSD和HGMD数据库中均无记录,通过高分辨率熔解曲线分析,在220个对照组中也没有发现该突变。2.患者IV:4的全外显子组测序结果用于检测其他27种已确认的先天性心脏畸形基因和130种孟德尔心脏疾病基因。该测序共识别了36412个单核苷酸多态性和2342个插入缺失,其中83个单核苷酸多态性和389个插入缺失通过了筛选标准。在上述157个基因中,1个ZASP的单核苷酸多态性被检测到,2个的插入缺失分别在ACTN2和MICA基因上被检测到,但均未从患病成员中共分离。通过筛选标准的单核苷酸多态性和插入缺失的其他基因,全都用已发表文献进行复核,但没有先天性心脏病的相关基因被发现。3.从进化上讲,从果蝇到人类,该赖氨酸突变位点都高度保守,我们认为它就是GATA4蛋白的甲基化位点。通过polyphen2,SIFT和Mutation Taster软件预测可知,p.K300T变异型可能影响蛋白质功能,并导致发病(可能性:0.9999)。种种预测都证明该变异型是有害的,并导致该家族ASD或VSD的发病。结论:1.本研究报道了一个涉及68位家庭成员由4代人组成的中国房间隔缺损家系。2.我们发现了一种新型的GATA4基因变异型(c.A899C,p.K300T)。本研究首次报道了该GATA4变异型的甲基化位点与房间隔缺损相关,拓宽了GATA4基因的变异频谱。3.全外显子组测序技术是分析家系遗传致病基因的经济有效的方法。
[Abstract]:Congenital heart disease is a very common birth defects, with high morbidity and mortality, the incidence rate is about 8/1000 to twelve [1]. of atrial septal defect about all congenital heart disease accounted for 10% of adult congenital heart disease 20%-30%[2]. anatomically, it is because of the atrial septal defect or lack of blood circulation caused by directly in the heart room. At present, there are more than 10 kinds of encoding transcription factors or cofactors (NKX2.5, GATA4, TBX5, TBX20, and, CITED2) structure of sarcomere protein (ACTC1, MYH6, MYH7, and, MYBPC3), metal protease (TLL1) genes were found with genetic room septal defect. Among them, GATA4 and NKX2.5 GATA4 gene mutation [3,4]. with high penetrance consists of 7 exons, encoding a zinc finger transcription factor GATA4, it exists in multiple heart development related gene [5]. in the promoter according to The research reported in the human gene mutation database, a variant of 123 GATA4 can be caused by congenital heart disease, such as tetralogy of Fallot, atrial septal defect, ventricular septal defect and dilated cardiomyopathy.GATA4 binding protein encoding a zinc finger transcription factor, which plays an important role in the growth process and the heart the formation of embryos. In this paper, we research on a 4 generation Chinese family, discovered a new variant of GATA4 (c.A899C, p.K300T), it appears in all affected members and two incomplete penetrance of the mutation carriers who are not found in the control. In the group, and there are no reports in the literature, in the human single nucleotide variation database (DB, SNP) genome variation database (EVSD) and the human gene mutation database (HGMD) are not recorded. Bioinformatics software (The polyphen2, SIFT and Mutation Ta Ster) predicted that the variant is harmful. From Drosophila to humans, lysine sites of the variant in has been highly conservative, and is considered the methylation sites of GATA4 protein. The transcriptional activity of GATA4 mice decreased, methylated amino acids have been confirmed related to heart development. Our research expands the mutation spectrum of GATA4 gene, and first reported the methylation sites and the GATA4 room variant. Septal defect Objective: to find and identify a spanning 4 generations, genes involving 68 people of ASD family and mutation. Methods: using whole exome sequencing and multiple sequence comparison and bioinformatics method combining predictive of the atrial septal defect family genetic analysis. Results: in all 1. affected family members (II:6, III:4, III:5, III:11, III:26, III:31, IV:1, IV:4) and two unaffected carriers (II:10, I II:1) of the GATA4 gene exon 4, discovered a new variant of non synonymous mutations (c.A899C, p.K300T). In DB SNP, EVSD and HGMD were not recorded in the database, by high resolution melting curve analysis, 220 in the control group did not find the mutation in.2. patients. IV:4 the whole exome sequencing results for the detection of the other 27 confirmed congenital heart disease genes and 130 Mendel heart disease gene. The sequencing identified 36412 SNPs and 2342 indels, including 83 SNPs and 389 is inserted into the through screening criteria. In the absence of these 157 genes, single nucleotide polymorphism of 1 ZASP were detected, 2 of the insertion and deletion respectively in ACTN2 and MICA genes were detected, but were not isolated from diseased members. By screening standard single nucleotide polymorphisms and insertion deletion Other genes, with all the published literature review, related genes but without congenital heart disease was found in.3. from an evolutionary perspective, from Drosophila to humans, the lysine mutation sites are highly conserved, we believe that it is the GATA4 protein methylation sites. Through polyphen2, SIFT and Mutation by Taster software the p.K300T variant may affect protein function, and cause disease (possibility: 0.9999). The prediction shows that the variant is harmful, and cause the disease in the family of ASD or VSD. Conclusion: 1. this study reported one involving 68 family members consisting of 4 generation Chinese atrial septal defect family.2. we found a new type of GATA4 gene variant (c.A899C, p.K300T). This is the first report of the methylation sites and the GATA4 room variant of the septal defect related to broaden the spectrum of the.3. mutation GATA4 gene full Exon sequencing is an economical and effective method for analyzing genetic pathogenicity genes.

【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R725.4

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