TLR4基因多态性在中国人群中的初步研究

目的检测中国人Toll样受体4(Toll—like receptor 4．TLR4)基因调控区和编码区的单核苷酸多态性(single nucleotide polymorphisms，SNPs)．寻找TLR4基因的遗传标记。方法采用直接测序的方法检测基因的5′区、编码区、部分内含子区和3′区，以确定中国人群中TLR4基因SNP的位置和类型，并用聚合酶链反应-限制性片段长度多态性对重庆汉族样本进行了抽样调查。结果在4．98kb的测序范围内，发现5个新的SNP，3个位于5′区．2个位于3′非翻译区。在重庆地区汉族样本中．两个高频分布SNP的等位基因频率分别是0．266和0．404。结论在TLR4基因新发现的两个高频多态性位点在我国人群中比较常见，可以作为关联分析的遗传标记。     

SCN7A 基因单核苷酸多态性与原发性与原发性高血压的相关研究

目的　检测中国人电压调控钠通道 7型α亚单位基因 (sodium channel,voltage- gated,type ,alpha polypeptide,SCN7A)调控区和编码区的单核苷酸多态性 (single nucleotide polymorphisms,SNPs) ,并探讨其与上海汉族人群原发性高血压的关系。　方法　采用直接测序法检测基因启动子、编码区和部分内含子的序列 ,以确定中国人群中 SCN7A基因 SNPs的位置及类型。采用聚合酶链反应 -限制性片段长度多态性及直接测序法 ,对上海汉族 96例原发性高血压患者和 96名正常血压对照者进行 SNP检测和关联研究。对所发现的 P<0 .0 5的 SNP位点 ,进一步扩大样本 (病例、对照组各 2 88例 )加以验证。结果　在 13132 bp的测序长度中 ,共发现 32个 SNP,包括启动子区 7个 ,编码区 10个 (其中改变氨基酸编码的 6个 ) ,3′非编码区 1个 ,内含子区 14个 ,其中 30个为新发现的 SNP。关联研究结果显示 SNP0 2 1在病例和对照组中的分布差异存在显著性 (P <0 .0 1) ,该 SNP多态可改变氨基酸的编码序列。　结论SCN7A基因变异可能与上海汉族人群原发性高血压相关。     

AD7C-NTP基因的染色体定位及其产物的跨膜区预测

目的 :对AD7C NTP基因进行染色体定位 ,预测其编码产物的跨膜区。方法 :用Blat服务器进行AD7C NTPmRNA序列与基因组DNA序列的比对。借助PHDhtm、TMHMM2 .0、HMM TOP2 .0、SMART和PSORT等服务器 ,预测AD7C NTP基因编码产物的跨膜特征及其亚细胞定位。结果 :AD7C NTP基因定位于 1p36 .11负链 ,无内含子序列。AD7C NTP基因编码产物具有 3个跨膜区 ,可能定位于过氧化物酶体。结论 :对AD7C NTP基因及其产物的生物信息学分析为后续的基因克隆及功能研究提供了有益的线索     

中国人膜联蛋白A1基因单核苷酸多态性及其与2型糖尿病的相关性

目的　筛查上海地区汉族人群中膜联蛋白 A1(annexin A1,ANXA1)基因的单核苷酸多态性 (single nucleotide polymorphisms,SNPs) ,并通过关联分析研究其与 2型糖尿病的相关性。方法　选取2 4例 2型糖尿病患者的 DNA样本 ,采用直接测序法对 ANXA1基因的启动子区、全部外显子及其临近内含子区作 SNPs筛查 ,并在其余的 171例 2型糖尿病和 189名正常对照间作进一步的基因分型。结果ANXA1基因测序长度 6 798bp,共检出 7个 SNPs,其中启动子区 2个 (- 7974 C>T,- 70 4 0 G>T) ,内含子区 3个 ( 90 5 9A>G, 92 0 4 C>T, 10 4 86 A>G) ,5′-非翻译区 1个 (- 6 6 14 A>G) ,编码区 1个( 1784 A>G)。进一步的基因分型后显示这些 SNPs的等位基因频率在 2型糖尿病和正常对照组之间差异无显著性 (P>0 .0 5 )。结论　ANXA1基因多态性与上海地区汉族人群中 2型糖尿病无显著相关性。     

颅内海绵状血管瘤 CCM1基因第12外显子及其5′端内含子新突变位点

目的　探讨 CCM1基因突变在中国人颅内海绵状血管瘤 ( intracranial cavernous angiomas,ICCA)发病中所起的作用。方法　收集我院神经外科 2 0 0 2年 6月～ 2 0 0 3年 2月收治并经手术病理证实的2 1例 ICCA患者及 15名正常健康对照者 ,从外周静脉血中提取 DNA,PCR法扩增 CCM1基因第 12外显子及其两侧部分内含子序列 ,应用 DNA直接测序技术对扩增产物进行检测。结果　 5例患者中检测出 3处 CCM1基因突变 ,均为首次发现。其中 ,5例患者中均存在 1172 C→ T的错义突变 ,使编码 KRIT1蛋白391位的氨基酸由丝氨酸变成苯丙氨酸。另有 1例患者存在 116 0 A→ C的错义突变 ,使编码 KRIT1蛋白387位氨基酸的谷氨酰胺变成脯氨酸。另一个突变发生在第 12外显子 5′端内含子区域 ,5例患者中有 4例第 4个碱基 C被 T取代。对照组检测结果无异常。结论　中国 ICCA患者存在 CCM1基因第 12外显子的突变 ,并与 ICCA的发病有关     

中国汉族人HIV-1协同受体CXCR4基因编码区新的突变位点研究

目的 对中国汉族人群HIV—1协同受体CXCR4编码区的基因多态性进行研究，为中国的获得性免疫缺陷综合征(AIDS)防治提供依据。方法 CXCR4(cDNA编号AFl47204)编码区用2对引物进行PCR扩增，然后分别测序，测序样本数为48例。用DNAstar分析测序结果，寻找SNP位点。结果 在编码区发现了7个SNP位点，其中3个同义突变(129位C→T、426位C→T，968C→T)，3个有义突变(38位C→T、90位A→T、712位A→C)，1个终止突变(106位C→T使谷氨酸密码子变成终止密码子)。其中38位C→T、90位A→T、712位A→C、106位C→T，基因突变频率为4．2％、4．2％、9、4％和3．1％。结论 在CXCR4编码区找到的7个SNP位点中，4个引起氨基酸改变，1个已有报道，对HIV—1感染和AIDS病程的影响值得研究。     

亚洲带绦虫成虫延伸因子-1基因的克隆和分析

目的分析和预测亚洲带绦虫成虫延伸因子-1（elongation factor 1,EF-1）基因及其编码的蛋白的结构和功能。方法利用生物信息网站如美国国家生物技术信息中心（NCBI,http：∥www.ncbi.nlm.nih.gov/）和瑞士生物信息学研究所的蛋白分析专家系统（ExPASY,http：∥ca.expasy.org/）中有关基因和蛋白的序列和结构信息分析的各种工具,结合其它生物信息学分析软件包,从亚洲带绦虫成虫全长cDNA质粒文库中识别延伸因子-1的全长编码基因并预测其蛋白的结构和功能。结果该基因是全长基因,长度988bp,编码区为67～868,编码269个氨基酸,无跨膜区;与GenBank中细粒棘球绦虫同源基因的一致性达87%,相似性达91%;预测三个主要的抗原表位位于135～140,126～131,157～162。结论应用生物信息方法从亚洲带绦虫成虫cDNA文库中筛选出EF-1基因。     

中国汉族人CC趋化因子受体-5基因新的突变位点及多态性分析

目的：调查中国汉族人群人类免疫缺陷病毒－1协同受体CC趋化因子受体-5[chemokine (CC)receptor 5,CCR5]编码区的基因多态性位点，为艾滋病的防治提供依据。方法：CCR5编码区用两对引物进行PCR扩增，设计测序引物依次测序，样本数为42份，用DNAstar分析测序结果，寻找单核苷酸多态性（single nucleotide polymorphism,SNP)位点。结果：在编码区共发现6个SNP位点，4个引起氨基酸改变：A184G、G503T、G668A、G999T；1个单碱基缺失，引起移码突变和提前终止。A184G、G503T、G999T3个中国汉族人所特有的SNP位点为首次发现，等位基因频率分别为1．2％，39．0％和9．5％；其中G503T分布明显不符合Hardy-Weinberg平衡。结论：中国汉族人CCR5编码区SNP位点有自己的特点，与高加索人和非洲人明显不同，与日本人也不完全一致。     

人类MOG1基因检测及其与青壮年猝死综合征的相关性研究

目的寻找MOG1基因的变异位点,探讨其与青壮年猝死综合征的关系。方法提取青壮年猝死综合征病例组及健康对照组的基因组DNA,采用聚合酶链式反应（PCR）方法扩增MOG1基因编码区外显子、外显子-内含子交界区以及3′侧翼区序列,直接行DNA测序以明确遗传变异类型,并进行统计学分析。结果在病例组中共检测到3个变异位点,其中2个为新发现的突变,分别为c.285G〉C（p.L95L）和c.＊4C〉T,另1个为单核苷酸多态性位点c.437＋16C〉T。在病例组和对照组中c.437＋16C〉T位点基因型分布（P=0.071）和等位基因频率（P=0.819）存在一定程度差异,但差异均无统计学意义。结论MOG1基因是否是中国人青壮年猝死综合征的易感基因还有待进一步研究。     

一例Rotor综合征患儿的基因变异分析

目的探讨1例Rotor综合征患儿的遗传学病因。方法收集患儿的临床资料,应用高通量测序技术对患者行全外显子组测序并进行Sanger测序验证。用单管三引物PCR分析法检测SLCO1B3基因第5内含子长散布元件-1(long-interspersed element-1,LINE-1)的插入情况。结果高通量全外显子组测序发现患儿携带SLCO1B1基因c.1738C>T纯合无义变异。SLCO1B3基因第5内含子中LINE-1的纯合插入,导致第5外显子或第5~7外显子跳跃,并在SLCO1B3转录本中引入了终止密码子。结论SLCO1B1基因c.1738C>T纯合变异以及SLCO1B3基因第5内含子LINE-1的纯合插入可能是该Rotor综合征患儿的致病原因。     

广东地区汉族人群TLR1 基因多态性的测序研究

目的: 人类Toll样受体1(TLR1)在先天性免疫中起着重要作用。本文将着重研究广东地区汉族正常人群中TLR1 基因功能区的单核苷酸多态性(SNPs)图谱和频率分布。方法: 随机收集50例健康、无亲缘关系的中国广东地区汉族人外周血液,对TLR1 基因的启动子区、5'和3'非翻译区、4个外显子区的序列进行PCR扩增和直接测序,找出多态性位点及其频率分布规律。在此基础上对多态性位点进行Hardy-Weinberg平衡分析、中性进化分析和连锁不平衡分析。结果: 共发现17个SNPs以及2个插入/缺失多态位点,其中2个是首次发现的新多态性位点。位于编码区的新SNP位点+1 378 A/G为非同义突变位点,能导致460位丝氨酸(Ser)残基替换为甘氨酸(Gly)残基,并且这个氨基酸残基的替换处于TLR1胞外区的LRR结构域中,从而有可能影响蛋白的识别功能。另外,频率最高的SNPs是+743 A/G和+1 518 A/G,其次要等位基因频率均达到48%。所有多态性位点均符合Hardy-Weinberg平衡。中性检验显示广东汉族人群 TLR1 基因不符合中性进化假说,很可能是其调控区受到平衡选择作用的原因。连锁不平衡分析显示多态性位点-6 912 C/TA、-6 876 C/T、-6 399 C/T和-6 375 C/T之间,-6 847 A/G和-6 737 A/T之间,以及-5 984 -/CT、-5 531 A/G和-5 490 C/G之间完全连锁。结论: 本研究首次报道了汉族正常人群TLR1 基因的功能性多态性图谱,发现了一些种族特异性的多态性位点及频率分布规律,为今后开展汉族人基因多态性与疾病相关性研究打下一定的基础。     

Association studies of the IL-23R gene in autoimmune thyroid disease in the Japanese population

Autoimmune thyroid diseases (AITDs), including Graves' disease (GD) and Hashimoto's thyroiditis (HT), are caused by interplays of genetic factors and environmental triggers. Interleukin-23 and its receptor (IL-23R) guide T cells towards the Th17 phenotype. IL-23R single nucleotide polymorphisms (SNPs) have been shown to be associated with several autoimmune diseases, including Crohn's disease and rheumatoid arthritis, and Graves' ophthalmopathy (GO) in Caucasians. To determine whether variants in the IL-23R gene are associated with AITDs in Japanese, 464 Japanese AITD patients (290 with GD, 174 with HT) and 179 matched Japanese control subjects were genotyped for four SNPs spanning the IL-23R gene. SNPs rs11209026 and rs7530511 were genotyped using TaqMan allelic discrimination assays and SNPs rs2201841 and rs10889677 were genotyped using a fluorescent-based restriction fragment length polymorphism method. Case-control association studies were performed using the χ² and Fisher's exact tests with Yates correction. Of the four SNPs rs11209026 was non-polymorphic in our dataset. The other three SNPs were not associated with GD or GO or HT in our Japanese population. These results suggest that the IL-23R gene is associated with AITDs only in a specific ethnic group.     

Haplotypes of the 5' region of the IL-4 gene and SNPs in the intergene sequence between the IL-4 and IL-13 genes are associated with atopic asthma.

IL-4 and IL-13 are important in IgE synthesis and allergic inflammation. Therefore, genes encoding IL-4 and IL-13 are candidates for predisposition to asthma and atopy. A recent study in the YAC transgenic mouse has revealed that one of the conserved noncoding sequences (CNS-1) between IL-4 and IL-13 influences the expression of IL-4, IL-5, and IL-13, suggesting that CNS-1 acts as a coordinate regulator of these genes. This investigation screened for mutations in the 13-kb region between IL-4 and IL-13, which includes the human equivalent of the murine CNS-1. Four single nucleotide polymorphisms (SNPs) were found in the region between IL-4 and IL-13 (IL-4-IL-13SNP1, IL-4-IL-13SNP2, IL-4-IL-13SNP3, and IL-4-IL-13SNP4). There was no mutation in the human CNS-1. We genotyped these and other previously reported polymorphisms in IL-4 and IL-13 using asthmatic families, and examined association by transmission disequilibrium test. Two-locus haplotype analysis revealed that haplotypes composed of the IL-4 RP2del, IL-4 +33T, or IL-4 -589T alleles and either IL-4-IL-13SNP3G or IL-4-IL-13SNP4C are transmitted significantly to asthma-affected children (p = 0.002). This data suggests that haplotypes composed of the 5' region polymorphisms in the IL-4 gene and SNPs in the intergene sequence between IL-4 and IL-13 influence the development of asthma.     

Comprehensive association study of genetic variants in the IL-1 gene family in systemic juvenile idiopathic arthritis

Patients with systemic juvenile idiopathic arthritis (sJIA) have a characteristic daily spiking fever and elevated levels of inflammatory cytokines. Members of the interleukin-1 (IL-1) gene family have been implicated in various inflammatory and autoimmune diseases, and treatment with the IL-1 receptor antagonist, Anakinra, shows remarkable improvement in some patients. This work describes the most comprehensive investigation to date of the involvement of the IL-1 gene family in sJIA. A two-stage case-control association study was performed to investigate the two clusters of IL-1 family genes using a tagging single nucleotide polymorphism (SNP) approach. Genotyping data of 130 sJIA patients and 151 controls from stage 1 highlighted eight SNPs in the IL1 ligand cluster region and two SNPs in the IL1 receptor cluster region as showing a significant frequency difference between the populations. These 10 SNPs were typed in an additional 105 sJIA patients and 184 controls in stage 2. Meta-analysis of the genotypes from both stages showed that three IL1 ligand cluster SNPs (rs6712572, rs2071374 and rs1688075) and one IL1 receptor cluster SNP (rs12712122) show evidence of significant association with sJIA. These results indicate that there may be aberrant control of the activity of the IL-1 family in sJIA patients causing the increased susceptibility to the disease.     

Identification of novel SNPs in the interleukin 6 receptor gene (IL6R)

The human interleukin-6 receptor (IL6R) is responsible for signal transduction of IL6 that might have associations with immune diseases and various infectious diseases. We have sequenced all 10 exons including the putative splicing site to identify single nucleotide polymorphisms in IL6R. Seven novel single nucleotide polymorphisms (SNPs) were identified; one SNP in the promoter region (-183G>A), one synonymous SNP in exon 2 (24013G>A: Ala31Ala), one non-synonymous SNP in exon 9 (48892A>C: Asp358Ala) and four in introns (29753A>C, 42700T>C, 48869T>A and 59818C>T). The frequencies of each SNP in the Korean population (n=300) were 0.48 (-183 G>A), 0.13 (24013 G>A), 0.41 (29753A>C), 0.41 (42700T>C), 0.1 (48869T>A), 0.42 (48892A>C), and 0.07 (59818C>T), respectively. Haplotypes and their frequencies were estimated by the EM algorithm. Linkage disequilibrium coefficients (/D'/) between each SNP pair were also calculated. The information on SNPs and haplotypes in IL6R would be useful for genetic studies of this gene.