老年痴呆关联基因的研究进展

阿尔茨海默类痴呆（AD）是老年痴呆中最常见的一种,它以渐进性的神经功能退化并伴随着整体认知能力的下降为特征。早发性AD主要是由β-淀粉样前体蛋白（APP）基因和早老素基因突变引起,而与晚发性AD发病明显相关的只有载脂蛋白E-ε4 ( APOE-ε4)等位基因。但是APOE-ε4等位基因对AD发病既非充分又非必要,而且只能解释少于50%的AD的遗传变异。所以有必要进一步寻找与AD的关联基因。 Abstract:Dementia of the Alzheimer type (AD) is the leading cause of dementias for the elders.It is a progressively neurodegenerative disorder characterized by global cognitive decline.While most of the rare early-onset AD can be explained by mutations in APP gene and presenilin genes,the genetic etiology of the more common late-onset AD is only partly explained by the APOE-ε4 genotype.But the APOE-ε4 allele is neither necessary nor sufficient to cause disease and it can only account for less than one-half of the genetic variance of AD.Thus,more genes involved in AD are our special attention.     

低密度脂蛋白受体相关蛋白基因C766T多态性与阿尔茨海默氏病发病风险的Meta-分析

运用Meta分析的方法综合评价低密度脂蛋白受体相关蛋白基因(lowdensitylipoproteinreceptor-relatedprotein1gene,LPR-1)第三外显子C766T多态性与阿尔茨海默氏病(Alzheimer’sdisease,AD)发病风险的关系。通过检索Medline、Cochrane图书馆和中国生物医学文献数据库(CBM),纳入内容涉及LPR-1基因C766T多态性的基因型频率和(或)等位基因频率的独立病例对照研究。各文献满足研究方法相似,有综合的统计指标。研究年限为1997~2004年,语种不限。应用RevMan4.2软件进行统计分析。在AD组3764例和对照组3647例研究对象中,分别对基因型和等位基因频率做合并统计。各研究之间有显著的异质性,P<0.01,故采用随机效应模型分析合并结果。总体效应检验未发现CC基因型频率在病例对照之间统计学上的差异(Z=1.74,P=0.08,OR=1.17,95%CI:0.98~1.39),C等位基因频率在病例对照之间也未发现差异(Z=1.31,P=0.19,OR=1.11,95%CI:0.95~1.31)。Meta分析结果提示,LPR-1基因C766T多态性不是AD的主要风险因子,但尚不能完全排除其可能在AD发病中具有微弱的作用。     

Alzheimer氏病相关基因的研究进展

Ａｌｚｈｅｉｍｅｒ 氏病是发生于老年人的一种原发性退行性脑病,发病率较高。是当今生物医学热点研究之一。本文概述了Ａｌｚｈｅｉｍｅｒ 氏病相关基因的研究概况,对其发病机理的可能的三种学说以及Ａｌｚｈｅｉｍｅｒ 氏病的诊断和治疗进行了阐述。     

IL-23 受体基因多态性和克罗恩病的相关性研究

目的:探讨白介素23受体(IL-23R)基因rs11465779位点多态性与克罗恩病(Crohn’s Disease,CD)的关系。方法:从98例上海本地汉族CD患者和90例正常对照者外周血标本中提取基因IBD组DNA,用聚合酶链式反应-限制性片段长度多态(PCR-RFLP)技术检测IL-23R基因rs11465779位点变异情况,分析其基因表型、基因频率与IBD的关系。结果:IL-23R基因rs11465779位点基因型和等位基因频率在CD组和对照组中分布差异无显著性(P>0.05),且该位点多态性和CD发病年龄及性别均无相关。结论:IL-23R基因rs11465779位点多态性变异,可能不是中国南方汉族人群CD发病的危险因素。     

中国人α珠蛋白基因3’HVR多态分布的研究

本文以3’HVR为探针,对来自全国17省市的51名无血缘关系的健康人进行P vuⅡ限制性片段长度的多态分析,发现3’HVR在片段大小的变异范围及基因频率的分布均有中国人的特点。结果表明,纯合子占15.7%,杂合子占84 .3%,102个等位基因共有34个长度不同的等位片段,大小从2.0-7.0kb之间呈连续分布, 主要分布在2.0-2.5kb及4.0-6.0kb,频率分别为0.43和0.34。并与刘国仰、余裕炉等的资料进行综合比较,初步揭示了中国人群中3’HVR的多态特点。 Abstract: 51 unrelated Chinese individuals from 17 different provinces and cities were typed for PvuII restiction fragment length polymorphism with the probe 3’HVR.The frequencies of homozygotes and heterozygotes were estimated as 15.7% and 84.3%,34 distinguishable allele sizes showed a continue distribution from 2.0-7.0kb.The main alleles of 2.0-2.5kb and 4.0-6.0kb gave the gene frequencies of 0.43 and 0.34 respectively.The preliminary characteristics of 3’HVR locus in Chinese population were revealed.     

中国人dystrophin基因RFLPs的初步研究

我们用dystrophin基因的cDNA全顺序(长14 kb)为核酸分子杂交探针,对中国人dystrophin基因内的RFLPs进行了初步研究。在结果中给出了PvuⅡ/1 a、Taq Ⅰ/2 b—3、PvuⅡ/2 b—3、TaqⅠ/5 b—7、Xba Ⅰ/10五种杂交中所见的六个RFLPs 的预期杂合频率和受检女性的实际杂合频率;其中PvuⅡ/2 b—3(A 1=26.0 kb,A 2=3.8 kb)和Taq Ⅰ/5 b—7(A 1=10.0 kb,A2=8.4 kb)的2个RFLPs为本文首次报道。PvuⅡ/1 a的2个RFLPs 的等位片段频率与日本人的同类研究结果比较,差异无显著性。但Taq Ⅰ/2 b—3、Taq Ⅰ/5 b—7、Taq Ⅰ/8、EcoR Ⅴ/9和Xba Ⅰ/10的5个RFLPs 与高加索人的数据比较,发现其中4个RFLPs 的等位片段频率的差异有极其显著性。这提示了东西方人在dystrophin 基因的分子结构上存在着较大的差别。在这些差异之中,Taq Ⅰ/2 b—3、Taq Ⅰ/8和EcoR Ⅴ/9检出的RFLPs 等位频率,中国人低于高加索人;而Xba Ⅰ/10检出的RFLPs 等位频率则显著高于高加索人;另外Taq Ⅰ/5 b—7检出的RFLPs的等位片段频率则与高加索人相近。实验结果还提示PvuⅡ/1 a、Taq Ⅰ/5 b—7和Xba Ⅰ/10这三种杂交,对于在中国人群中检测DMD/BMD 基因携带者以及产前诊断,具有很高的应用价值。     

中国人α珠蛋白基因3′HVR多态分布的研究

本文以3’HVR为探针,对来自全国17省市的51名无血缘关系的健康人进行PvuⅡ限制性片段长度的多态分析,发现3’HVR在片段大小的变异范围及基因频率的分布上均有中国人的特点．结果表明,纯合子占15.7％,杂合子占84.3％,102个等位基因共有34个长度不同的等位片段,大小从2．0－70kb之间里连续分布,主要分布在2．0－25kb及4.0－6．0kb,频率分别为0．43和0．34．并与刘国仰、余裕炉等的资料进行综合比较,初步揭示了中国人群中3’HVR的多态特点．     

ACE基因I/D多态与冠心病的遗传流行病学研究——表型不一致同胞对分析和传递不平衡检验

用表型不一致同胞对分析(DSP)和传递不平衡检验(TDT),在冠心病家系中探讨血管紧张素转换酶(ACE)基因内含子16中的插入/缺失(I/D)多态是否为冠心病的遗传易患因素。方法：1998年10月～1999年2月期间收集先证者一级亲属中至少有1例冠心病患者的家系45个,其中完整核心家系、父母一方、双方基因型缺失家系分别为21、2与22个,调查对象212人。PCR-RFLP方法鉴定ACE基因I/D多态性基因座基因型。条件Logistic回归进行DSP分析,TDT-STDT 1.1程序进行TDT、STDT检验。结果表明,45个冠心病家系共组成106对DSP,单变量条件Logistic回归及调整传统危险因素后的多变量条件logistic回归均未发现II、ID和DD基因型在表型不一致同胞对中的分布存在差别。对13个满足要求的核心家系进行TDT检验,杂合子父母传递给患病子代的D等位基因频率未显著偏离50％(P>0.05);24个满足要求的同胞组进行STDT检验亦未发现受累子代与非受累子代D等位基因分布有显著差异(P>0.05)。结论:在冠心病家系中未发现ACE基因I/D多态与冠心病存在关联或与疾病基因座存在连锁,说明该基因座可能不是国人冠心病的遗传易患基因。 Abstract:To investigate whether the insertion/deletion polymorphism of the human angiotensin I converting enzyme gene increased the risk of coronary heart disease (CHD) in CHD pedigrees,discordant sib pair analysis (DSP) and transmission/disequilibrium test (TDT) were used.Forty-five CHD pedigrees with at least one CHD patient in the first degree relatives of probands were recruited during Oct.1998 to Feb.1999,of which parental genotype known,one or both parental genotype missing was 21,2 and 22 respectively.ACE genotype was measured by PCR technique.Conditional Logistic regression was used to analyze the DSP,and TDT-STDT program 1.1 was used for TDT and STDT.Univariable conditional Logistic regression did not find significant difference of the distribution of three different ACE genotypes in the 106 discordant sib pairs obtained from the 45 pedigrees.After adjusting effects of traditional risk factors of CHD,no significant difference of the distribution was found by multiple Logistic regression model.Neither the TDT for 13 nuclear families or STDT(sib transmission/disequilibrium test) for 24 sibships showed significant difference between the transmitted and untransmitted ACE gene D allele distributions.Our results show that the insertion/deletion polymorphism of ACE gene is not associated or linked with CHD in Chinese population.     

青海湖裸鲤mtDNA遗传多样性的初步研究

本文用BclⅠ、AvaⅠ、BamHⅠ、PstⅠ、KpnⅠ、PvuⅡ共6种限制性内切核酸酶,分析了15尾青海湖裸鲤mtDNA的限制性片段长度多态性,共检测出20个酶切位点,发现BclⅠ、BamHⅠ和PvuⅡ三种酶切类型具有多态性.根据不同个体mtDNA的酶切类型,青海湖裸鲤存在4种mtDNA单倍型,计算mtDNA多态度π值为0.0043,初步认为青海湖裸鲤在线粒体DNA上存在较丰富的群体内变异、 Abstract:An analysis of patterns of cleavage of mtDNA by restriction endonucleases was performed for 15 Gymnocypris przewalskii przewalskii.Mitochondrial DNA polymorphisms were detected in the restriction patterns generated by the following 5 enzymes,BclI,AvaI,BamH],PstI,KpnI,PvuII.Only 3 of them (BclI,BantHI,PvuII) were found to be polymorphisms.Our results shorted that there were 4 mtDNA haplotypes in Gyrnnocypris przewalskii przewalskii and the genetic divergenec(π)was 0.0043,which indicated that mtDNA genetic diversity in Gymnocypris przewalskii przewalskii is higher.     

中国人胃癌和正常组织基因组DNA中癌基因Ha-ras的限制性片段长度多态性研究

本文报道以PHS-49为探针,分析了中国人群中36例胃癌患者癌组织和25位正常人体组织基因组DNA中Ha-ras基因的BamHI限制性片段长度多态性(RFLPs)。发现了10种不同长度的片段和18种基因型。其中4种小于6kb的BamHI片段是迄今国外未见报道的,这可能是中国人群遗传多态性的一个特征。此外,在胃癌组织中发现Ha-ras的一些稀有等位基因和基因型的频率明显高于正常人群。对两名胃癌患者家系中的11名成员也作了RFLPs分析,发现有些成员出现3条和4条限制性片段的杂合个体,表明这些个体的染色体上含有的Ha-ras基因不只一份拷贝。对上述现象的可能原因作了分析和讨论。     

eNOS基因第四内含子a／b多态与湖北汉族人原发性高血压而不是2型糖尿病相关联

目的：探讨内皮型一氧化氮合酶基因（eNOS）与湖北汉族人原发性高血压（EH）和2型糖尿病（T2DM）的关系。方法：采用病例-对照设计,分析了657例样本eNOS第四内含子重复序列多态性a／b,测量了身高、体重、腰围、臀围、收缩压、舒张压、空腹血糖,餐后2小时血糖等临床指标。结果：EH病例组eNOSab＋aa基因型和a等位基因频率显著高于EH对照组（基因型：25．3％vs18．9％,P=0．049;等位基因：13．3％vs9．8％,P=0．045）;而T2DM病例组与T2DM对照组的eNOSab＋aa基因型频率没有显著差异（20．2％vs24．1％,P=0．247）。单因素Logistic回归分析显示eNOSab＋aa基因型是EH的危险因子（OR=1．623,95％CI 1．053—2．506,P=0．029）。多因素回归分析显示,EH的独立风险因素是年龄、体重指数和eNOS基因a／b多态性,而体重指数和腰臀比是T2DM的独立风险因素。结论：eNOS基因a／b多态性是湖北汉族人群EH的一个易感标记,而与T2DM没有相关性。     

eNOS基因第四内含子a/b多态与湖北汉族人原发性高血压而不是2型糖尿病相关亮

目的:探讨内皮型一氧化氮合酶基(eNOS)与湖北汉族人原发性高血压(EH)和2型糖尿病(T2DM)的关系.方法:采用病例一对照设计.分析了657例样本eNOS第四内含子重复序列多态性a/b,测量了身高、体重、腰围、臀围、收缩压、舒张压、空腹血糖,餐后2小时血糖等临床指标.结果:EH病例组eNOS ab+aa基因型和a等住基因频率显著高于EH对照组(基因型:25.3%vs 18.9%,P=0.049;等位基因:13.3%vs9.8%.P=0.045);而T2DM病例组与T2DM对照组的eNOS ab+aa基因型频率没有显著差异(20.2%vs24.1%,P=0.247).单因素Logistic回归分析显示eNOS ab+aa基因型是EH的危险因子(OR=1.623,95%CI 1.053-2.506,P=0.029).多因素回归分析显示,EH的独立风险因素是年龄、体重指数和eNOS基因a/b多态性,而体重指数和腰臀比是T2DM的独立风险因素.结论:eNOS基因a/b多态性是湖北汉族人群EH的一个易感标记,而与T2DM没有相关性.     

HVEM Gene Polymorphisms Are Associated with Sporadic Breast Cancer in Chinese Women

As a costimulatory molecule, Herpesvirus entry mediator (HVEM) can bind with several costimulatory members, thus HVEM plays different roles in T cell immunity. HVEM and its ligands have been involved in the pathogenesis of various autoimmune, inflammatory diseases and tumors. In the current study, we conducted a case-control study comparing polymorphisms of HVEM and breast cancer. Subjects included 575 females with breast cancer and 604 age-matched healthy controls. Six HVEM SNPs (rs2281852, rs1886730, rs2234163, rs11573979, rs2234165, and rs2234167) were genotyped by PCR-RFLP. The results showed significant differences in genotypes and alleles between rs1886730 and rs2234167 (P<0.05). One haplotype (CTGCGG) that was associated with breast cancer was found via haplotype analysis. Our research also indicated an association between polymorphisms of HVEM and clinicopathologic features, including lymph node metastasis, estrogen receptor, progesterone receptor and P53. Our results primarily indicate that polymorphisms of the HVEM gene were associated with the risk of sporadic breast cancer in northeast Chinese females.     

COL9A1 Gene Polymorphism Is Associated with Kashin-Beck Disease in a Northwest Chinese Han Population

Objective

We sought to determine whether genomic polymorphism in collagen IX genes (COL9A) was associated with Kashin-Beck disease (KBD).

Methods

Twenty seven single nucleotide polymorphisms (SNPs) in COL9AI, COL9A2 and COL9A3 were genotyped in 274 KBD cases and 248 healthy controls using the Sequenom MassARRAY system. Associations between the COL9A polymorphism and KBD risk were detected using an unconditional logistic regression model. Linkage disequilibrium (LD) and haplotypes analysis were performed with the Haploview software.

Results

After Bonferroni correction, the frequency distribution of genotypes in rs6910140 in COL9A1 was significantly different between the KBD and the control groups (X ² = 16.74, df = 2, P = 0.0002). Regression analysis showed that the allele “C” in SNP rs6910140 had a significant protective effect on KBD [odds ratio (OR) = 0.49, 95% confidence interval (CI) = 0.34–0.70, P = 0.0001]. The frequencies of alleles and genotypes in rs6910140 were significantly different among subjects of different KBD stages (allele: X ² = 7.82, df = 2, P = 0.02, genotype: X ² = 14.81, df = 4, P = 0.005). However, haplotype analysis did not detect any significant association between KBD and COL9A1, COL9A2 and COL9A3.

Conclusions

We observed a significant association between rs6910140 of COL9A1 and KBD, suggesting a role of COL9A1 in the development of KBD.     

Changes in Chromatin Structure Associated with Alzheimer's Disease

Abstract— The enzyme micrococcal nuclease was used to examine the accessibility of chromatin extracted from brains of 13 patients with senile and presenile dementia of the Alzheimer type. Compared with chromatin extracted from brains of 8 patients without neurological signs or brain pathology and brains of 7 patients with nonAlzheimer dementia, Alzheimer chromatin was less accessible to this enzyme-. Reduced accessibility was reflected by a reduced yield of mononucleosomes in comparison with dinucleosomes and larger oligomers. Both neuronal and glial chromatin were found to be similarly affected. The reduced yield of mononucleosomes from Alzheimer chromatin is not due to their increased breakdown, but is probably related to protein associated with the internucleosomal linker region that retards nuclease action. Dinucleosomes isolated from control and Alzheimer nuclease digests were examined for their protein complement. Three perchloric acid-soluble proteins situated in the histone HI region of sodium dodecyl sulfate (SDS) gels were present in elevated levels in Alzheimer dinucleosomes. These results represent the first example of altered chromosomal proteins associated with a diseased state of the brain.     

A Putatively Functional Polymorphism in the HTR2C Gene is Associated with Depressive Symptoms in White Females Reporting Significant Life Stress

Psychosocial stress is well known to be positively associated with subsequent depressive symptoms. Cortisol response to stress may be one of a number of biological mechanisms that links psychological stress to depressive symptoms, although the precise causal pathway remains unclear. Activity of the x-linked serotonin 5-HTR2C receptor has also been shown to be associated with depression and with clinical response to antidepressant medications. We recently demonstrated that variation in a single nucleotide polymorphism on the HTR2C gene, rs6318 (Ser23Cys), is associated with different cortisol release and short-term changes in affect in response to a series of stress tasks in the laboratory. Based on this observation, we decided to examine whether rs6318 might moderate the association between psychosocial stress and subsequent depressive symptoms. In the present study we use cross-sectional data from a large population-based sample of young adult White men (N = 2,366) and White women (N = 2,712) in the United States to test this moderation hypothesis. Specifically, we hypothesized that the association between self-reported stressful life events and depressive symptoms would be stronger among homozygous Ser23 C females and hemizygous Ser23 C males than among Cys23 G carriers. In separate within-sex analyses a genotype-by-life stress interaction was observed for women (p = .022) but not for men (p = .471). Homozygous Ser23 C women who reported high levels of life stress had depressive symptom scores that were about 0.3 standard deviations higher than female Cys23 G carriers with similarly high stress levels. In contrast, no appreciable difference in depressive symptoms was observed between genotypes at lower levels of stress. Our findings support prior work that suggests a functional SNP on the HTR2C gene may confer an increased risk for depressive symptoms in White women with a history of significant life stress.