中国南方单纯性先天性心脏病患者NKX2.5基因突变的研究

目的对中国南方地区单纯性先天性心脏病患者进行NKX2.5基因胚系突变的筛查,探讨其在单纯性先天性心脏病发生中的作用及基因型与表型的关系。方法应用聚合酶链反应(PCR)结合DNA测序技术,对我国南方地区224例单纯性先心病患者和121例健康个体进行NKX2.5基因(包括基因的编码区,5′和3′非翻译区以及外显子与内含子的连接区域)进行突变分析。结果 NKX2.5基因中未检测到致病突变,仅发现三种已报道的SNPs:rs2277963(c.63AG,GAAGAG,p.Glu21Glu),rs3729753(c.606GC,CTGCTC p.Leu202Leu)和rs703752(c.975-61 GT),基因型频率及等位基因频率与NCBI数据库中已报道的中国人群携带率无显著性差异。结论中国南方地区单纯性先心病患者中NKX2.5基因致病突变极少发生,其致病突变的发现可能限于某些家系或者有特殊表型的先心病患者中。NKX2.5基因在我国南方地区单纯性先天性心脏病中的致病作用有待进一步研究。     

心脏发育相关基因NKX2.5突变与三亚地区儿童先天性心脏病的相关性研究

目的探讨心脏发育相关基因NKX2.5突变与三亚地区儿童先天性心脏病(congenital heart disease,CHD)之间的相关性,进而为本地区该患儿的预防及治疗提供依据。方法选取2019年01-11月海南省三亚市人民医院确诊的33例CHD患儿作为观察组,同时入选30例健康儿童作为对照组,用PCR-DNA测序技术对两组儿童外周血中NKX2.5基因的外显子及其侧翼序列进行分析。测序完成后,对NKX2.5的2个外显子进行PCR扩增测序,将结果与GeneBank 中公布的DNA标准序列进行对比,观察是否发生突变。结果三亚地区33例CHD患儿NKX2.5测序显示,17例患儿的21位氨基酸和2例患儿的94位氨基酸的第3位碱基发生同义突变,且突变基因均位于外显子1;6例患儿的246位氨基酸的第3位碱基均发生突变,且位于外显子2的第一部分;3例患儿的2个杂合发生同义突变,且位于外显子2的第二部分。结论在三亚地区CHD患儿中,NKX2.5外显子发现了5个突变位点,这些突变位点与本地区CHD可能存在着紧密的相关性。     

先天性心脏病胎儿心肌转录因子GATA-4基因突变检测

目的分析先天性心脏病胎儿中GATA-4基因的突变情况，期望为进一步阐明先天性心脏病发病的分子机理提供新的实验依据。方法应用PCR—DNA测序技术在20例先心病胎儿病变部位的心肌组织中筛查GATA-4基因突变。结果20例中，在1例先心病胎儿（ASD、VSD）中检测到一个突变（V267M），位于外显予4；在3例先心病胎儿中发现编码241位氨基酸（半胱氨酸）密码子的第三位碱基均存在杂合同义突变（C→T），位于外显子3，并证实是一个单核苷酸多态性（SNP）位点（rsl062215）。结论GATA-4基因突变（V267M）可能与胎儿先天性心脏病发病有关：GATA-4723C／T基因多态性（rs1062215）与胎儿先天性心脏病的关系有待进一步证实。     

新疆维吾尔族房间隔缺损患者NKX2.5基因突变研究

目的探讨NKX2.5的基因突变与新疆地区维吾尔族房间隔缺损(atrial septal defect,ASD)之间的关系。方法收集120例散发型维吾尔族ASD患者和120例健康维吾尔族人群血液样本进行DNA提取、目的基因聚合酶链反应及测序,并与Gene Bank标准序列进行比较以识别NKX2.5基因变异,采用χ~2检验比较NKX2.5基因多态在ASD患者和健康对照者间的频率分布差异。结果 120例ASD患者中未检测出NKX2.5基因突变,而在病例组和对照组发现2个不改变氨基酸的单核苷酸多态(single nucleotide polymorphisms,SNP),c.63 AG多态(rs2277923)和c.606GC多态(rs3729753),两个多态位点在CHD患者和健康时照者间分布的比较无显著性差异(P0.05)。结论 NKX2.5基因突变与新疆维吾尔族ASD的发生之间相关性可能是间接的。     

BMP-2基因在先心病肺动脉高压患儿中的突变研究

目的研究先天性心脏病引起的肺动脉高压中国患儿中是否存在BMP-2基因的错义突变。方法在18个先心病肺动脉高压(PAH)患儿及250个健康儿童中,对BMP-2的整个编码区及所有剪切位点进行序列分析。结果在18个PAH患儿中发现了一个有意义的潜在的致病突变(c.T326C,p.V109A)。该错义突变位于BMP-2基因的保守序列,其编码的氨基酸改变可能影响BMP-2功能。结论本实验在先心病引起的肺动脉高压中国患儿中发现了一个潜在的致病突变,BMP-2基因可能是中国人肺动脉高压发病过程的一个潜在候选基因。     

弥漫大B细胞淋巴瘤中IgVH基因突变的初步研究

目前发现根据IgVH基因的体细胞突变状况有助于判断B细胞肿瘤的来源。IgVH基因以免疫球蛋白受体的形式表达于大多数B细胞淋巴瘤,检测IgVH基因的突变状况可能是追踪肿瘤发展阶段的一个有用方法。绝大多数弥漫大B细胞淋巴瘤（DLBCL）含有突变的VH基因,提示其曾经历过体细胞突变。然而在肿瘤细胞中这种体细胞突变是否仍在持续进行,即克隆内变异,以及如果存在克隆内变异,[第一段]     

鋅指转录因子ZIC3在内脏异位中的研究现状及进展

内脏异位是由于左右非对称性发育异常所致,常与胸腹腔器官的异常偏侧化有关。心脏经常受累,且心脏受累的严重程度通常决定其预后效果。内脏异位患者有特征性的心血管畸形、内脏器官的异常排列以及中线结构发育畸形。在内脏异位患者中第一个被发现有突变的基因是编码锌指转录因子的ZIC3。很多研究证实,ZIC3突变可导致X连锁内脏异位,而且在孤立性先心病中也发现了ZIC3的突变。至今,在内脏异位患者中发现有13个ZIC3突变,其中包括无义突变、错义突变、沉默突变、移码突变以及易位突变等。然而,ZIC3基因在内脏异位,特别是伴复杂先心病中的致病机理仍不是很清楚。本文就ZIC3结构、作用、突变以及其在内脏异位伴先心病中的研究现状及存在的问题做一综述。     

Nkx2.5基因与先天性心脏病

先天性心脏病(CHD)是人类出生缺陷中最常见的畸形,也是婴幼儿非感染性疾病中最主要的死亡原因。大量研究表明Nkx2.5是重要的转录因子,在心脏发育过程中起很重要的作用,该基因的突变将影响心脏发育导致先心病。本文就Nkx2.5基因与先心病的关系与最新进展予以综述。     

NKX3.1下调前列腺癌PC-3细胞中抗凋亡基因 bcl-2 的表达

目的: 研究前列腺特异转录因子NKX3.1对 bcl-2 基因表达以及前列腺癌细胞凋亡的影响。方法: 转染pcDNA3.1- NKX3.1 于前列腺癌PC-3细胞中,得到瞬时转染NKX3.1的PC-3细胞,通过RT-PCR和Western blotting方法研究NKX3.1对 bcl-2 基因的表达的影响,并通过EMSA技术,研究NKX3.1诱导 bcl-2 基因下调的分子机制;进一步通过流式细胞术、凋亡小体染色等方法研究NKX3.1对细胞凋亡的影响。结果: NKX3.1可明显下调PC-3细胞中 bcl-2 mRNA及Bcl-2蛋白的表达;EMSA结果证明NKX3.1可与 bcl-2 基因上游调控区中的NKX3.1结合元件相互作用;流式细胞术结果显示,PC-3细胞转染NKX3.1后,细胞凋亡数增加了1.41倍;用Hoechst 33258细胞染色发现NKX3.1可使PC-3细胞凋亡小体数量明显增加。结论: NKX3.1可下调抗凋亡基因 bcl-2 的表达,促进前列腺癌细胞凋亡。     

p53基因CD72 Arg／Pro多态性与肿瘤易感性研究进展

p53基因是迄今发现的与人类恶性肿瘤相关性最强的基因。过去对p53基因的丢失、突变、蛋白的表达做了大量研究。近年来研究发现，p53基因CD72 Arg／Pro多态性与多种肿瘤的发病有关联。本文拟对p53基因该多态位点与肿瘤的研究进展做一综述。     

Analyses of GATA4, NKX2.5, and TFAP2B genes in subjects from southern China with sporadic congenital heart disease

BackgroundCongenital heart disease is the most common birth defect in newborns in southern China. The germline mutations in GATA4, NKX2.5, and TFAP2B genes have been identified to be responsible for congenital heart disease. The frequency of GATA4, NKX2.5, and TFAP2B mutations in subjects with congenital heart disease in southern China and the correlation between their genotype and congenital heart disease phenotype are not known.MethodsWe screened germline mutations in the coding exons and the flanking intron sequences of the GATA4, NKX2.5, and TFAP2B genes in 224 congenital heart disease patients located in southern China by denaturing high-performance liquid chromatography and DNA sequencing.ResultsFifteen heterozygous mutations in the GATA4 gene were identified in 30 congenital heart disease patients, including a novel heterozygous missense mutation (c.788 C>G) of GATA4 in one patient with ventricular septal defect. A novel TFAP2B mutation (c.31 A>G) in a patient with endocardial cushion defect and an unreported novel TFAP2B variant (c.1006 G>A) in six patients suffering from tetralogy of Fallot (one patient), persistent truncus arteriosus (two patients) and patent ductus arteriosus (three patients) was found. There were no reported NKX2.5 mutations except for several single nucleotide polymorphisms in the patients.ConclusionThese results suggest that genomic GATA4 and TFAP2B missense mutations may be associated with nonfamilial congenital heart disease with diverse clinical phenotypes in patients with congenital heart disease from southern China. They also revealed that the variation of the NKX2.5 gene may not be a risk factor for sporadic patients with congenital heart disease in this population.     

Phenotypes with GATA4 or NKX2.5 mutations in familial atrial septal defect

Recently, GATA4 and NKX2.5 were reported as the disease genes of atrial septal defect (ASD) but the relationship between the locations of their mutations and phenotypes is not clear. We analyzed GATA4 and NKX2.5 mutations in 16 familial ASD cases, including four probands with atrioventricular conduction disturbance (AV block) and two with pulmonary stenosis (PS), by PCR and direct sequencing, and examined their phenotypes clinically. Five mutations, including two GATA4 and three NKX2.5 mutations, were identified in 31.3% of the probands with ASD, and three of them were novel. The two GATA4 mutations in the probands without AV block were S52F and E359Xfs (c.1075delG) that was reported previously, and three NKX2.5 mutations in the probands with AV block were A88Xfs (c.262delG), R190C, and T178M. Additionally, we observed some remarkable phenotypes, i.e., dextrocardia with E359Xfs (c.1075delG) and cribriform type ASD with R190C, both of which are expected to be clues for further investigations. Furthermore, progressive, most severe AV block was closely related with a missense mutation in a homeodomain or with a nonsense/frame-shift mutation of NKX2.5 for which classification has not been clearly proposed. This pinpoints essential sites of NKX2.5 in the development of the conduction system.