2个汉族肥厚型心肌病家系致病基因与TCAP基因的关系研究

目的:确定候选基因TCAP与两个汉族家系家族性肥厚型心肌病(HCM)之间的连锁关系.方法:在排除13个已知家族性HCM致病基因与这两个汉族家系家族性HCM的连锁关系基础上,选择TCAP基因作为这两个汉族HCM家系的候选致病基因,在其所在的染色体区域选取4个微卫星标记(Marker)进行单倍型连锁分析.结果:D17S1814、D17S838、D17Sac091178和D17S1818这4个微卫星标记在重组率θ=0时,家系1的LOD值在-2.689754～-0.645666范围内,家系2的LOD值在-1.396476～0.416726之间;在重组率θ=0.1时,两个家系中最大的LOD值仅为0.272605.结论:TCAP基因与这两个汉族家系的HCM无连锁关系,TCAP基因不是这两个家系的致病基因,提示这两个汉族家系的致病基因可能是全新的未知致病基因.     

两例46,XY同患17α-羟化酶缺陷症家系的临床和分子遗传学研究

目的 对一个有两例46,XY同患17α-羟化酶缺陷症的家系进行临床、生化和分子生物学研究,探讨纯合突变和杂合突变在促肾上腺皮质激素(ACTH)兴奋实验前后相关生物学指标的改变.方法 收集一个17α-羟化酶缺陷症家系患者及其他成员的临床和实验室资料,采用PCR产物直接测序方法检测17α-羟化酶基因(CYP17A1)序列;进行1h ACTH兴奋试验.结果 患者CYP17A1基因第6号外显子329位密码子发生了TAC329AA纯合突变,引起Tyr329Lys错义突变和以后的移码突变;携带该突变基因的杂合子在ACTH兴奋前后激素水平的变化介于纯合基因型与正常对照之间.结论 本研究家系中CYP17A1基因突变是17α-羟化酶缺陷症的致病基因,携带该突变基因的杂合子能导致一定程度的生物学功能变化.     

IL-17A基因和IL-17F基因多态性在评估扩张型心肌病发病风险和预后的意义

目的:评估白细胞介素17A(IL-17A)和IL-17F单核苷酸多态性(SNPs)与中国重庆地区汉族人群扩张型心肌病(DCM)发生风险和预后的关系。方法:选取112例DCM患者和125例年龄和性别相匹配的健康人群对照,采用聚和酶链反应-限制性内切酶片断长度多态性和DNA测序的方法对IL-17A基因rs2275913(G-197A)和IL-17F基因rs763780(7488C/T)两个功能性SNP进行基因分型,然后运用等统计学方法分析SNPs与DCM遗传易感性及预后的关系。结果:IL-17A基因SNP rs2275913(G-197A)携带_(AA)基因型的个体患DMC的风险是携带GG基因型个体的2.124倍(95%CI_(AA)=1.213-3.964,P_(AA)=0.007);在DCM患者中,rs2 275 913位点_(AA)基因型携带者在NYHA心功能分级Ⅳ级、左心室射血分数<35%及有病毒性心肌炎病史的患者中所占比例显著增高(P<0.05);未发现IL-17F基因SNP rs763780(7488C/T)与DCM的发病和预后相关。结论:本研究首次发现IL-17A基因rs2275913(G-197A)位点SNP可能与DCM的遗传易感性和预后相关。     

IL-17A基因多态性及血浆水平与病毒性心肌炎的相关性研究

目的:探讨白细胞介素17A(interleukin-17A,IL-17A)rs2275913(G-197A)位点单核苷酸多态性(single nucleotide polymorphisms,SNPs)及血浆水平与重庆汉族人群病毒性心肌炎(viral myocarditis,VMC)的关系。方法:收集VMC患者200例,根据病程将患者分为急性期组112例和恢复期组88例,并选择同期200例健康体检的正常人作为对照组,采用聚和酶链反应-限制性内切酶片断长度多态性(PCR-RFLP)、DNA测序等方法检测全部受试者IL-17A基因rs2275913(G-197A)位点SNP,采用酶联免疫吸附法(ELISA)测定两组血清IL-17水平。结果:VMC组IL-17A基因rs2275913(G-197A)多态位点AA基因型和A等位基因频率均显著高于对照组(P0.05),携带AA基因型及携带A等位基因(AA+AG基因型)可增加患VMC的易感性(矫正后ORAA=2.197,95%CIAA=1.208-4.279,PAA=0.003;矫正后ORAA+AG=2.051,95%CIAA+AG=1.134-3.995,PAA+AG=0.009)。VMC组血清IL-17水平明显高于对照组(P0.05),尤以急性期为著(P0.05)。不论是VMC组还是对照组,IL-17A基因rs2275913(G-197A)多态位点中含A等位基因(AA+AG)者血清IL-17水平均显著高于非A等位基因(GG)携带者(P0.01)。结论:IL-17A基因rs2275913位点SNP可能与中国重庆地区汉族人群VMC有关,A等位基因是VMC的易感基因。     

成纤维滑膜细胞p53基因表达对类风湿关节炎患者CD4+T淋巴细胞的调节

目的 研究人成纤维滑膜细胞(FLS)p53基因表达对类风湿关节炎(RA)患者CD4+T淋巴细胞的调节作用.方法 采用小分子干扰RNA(siRNA)转染抑制FKS内p53基因表达,并与RA患者外周血CD4+T淋巴细胞共同培养.检测转染后FLS中骨保护素(OPG)表达及白细胞介素(IL)-6分泌.并对与之共培养的CD4+细胞膜胞质内蛋白干扰素(IFN)-γ、IL-17、IL-4和CD25以及IFN-γ孤儿核受体γt(RORγt)、IL-17、Foxp3 RNA水平进行测定.结果 p53基因被抑制后,FLS分泌IL-6减少,但OPG表达未受影响.p53基因被抑制的FLS使共培养的CD4+T淋巴细胞内IL-17及IFN-γ蛋白和RNA表达上调,但对CD4+T淋巴细胞RORγt RNA影响不大.虽可上调Foxp3表达,但CD4+CD25high细胞阳性率并无明显变化.结论 FKS内D53表达对RA外周血Th1、Th17有调节作用.     

老年性痴呆中载脂蛋白E与淀粉样β蛋白前体的关系

目的探讨老年性痴呆(Alzheimerdisease,AD)中载脂蛋白E(apolipoprotein E,ApoE)基因多态性与淀粉样β蛋白前体16-17外显子(App16-17)表达之间的关系。方法应用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)技术,检测25例Alzheimer痴呆(AD)患者、25例血管性痴呆(VD)患者及25例健康老年人的ApoE基因型,同时应用相对定量的竞争RNA扩增聚合酶链反应(RT-PCR)技术,检测上述患者外周血单核细胞中App16-17表达量。结果AD组患者ApoEε4等位基因频率较对照组升高(P<0.01),APOEε4等位基因携带者App16-17表达量较ε2、ε3高,但差异无显著性。结论ApoEε4基因为老年性痴呆的危险因子,ApoEε4等位基因对AD患者的App16-17表达量无显著性的影响。     

IL-17基因多态性与中国汉族人群炎症性肠病的关系

目的:研究IL-17A和IL-17F的5个多态性位点与中国汉族人炎症性肠病之间的关系.方法:采用病例-对照研究方法,收集确诊的溃疡性结肠炎(ulcerative colitis,UC)和克罗恩病(Crohn’s disease,CD)患者共350例(UC270例;CD80例),健康对照组268例,收集外周血标本2mL,提取DNA,运用LDR(ligasedetection reaction allelic)技术进行多态性检测.采用SPSS17.0软件进行数据分析.结果:CD患者中IL-17F(rs763780,7488T/C)突变等位基因C的频率明显高于对照组(13.8%vs8.4%,P=0.044,OR=1.74,95%CI1.01-2.99).在亚型分析中,rs763780基因多态性与CD病变范围有关,突变等位基因C在CD回结肠型患者中的频率明显高于对照组(P=0.02).IL-17A(rs2275913,G-197A)与UC患者疾病的严重程度有弱相关性,含有突变基因A的患者倾向于临床轻型.IL-17F(rs763780,7488T/C)多态性与U C患者发病年龄之间有弱相关性,T/C基因型患者趋向于年轻型(P=0.046).结论:IL-17F rs763780基因多态性与CD易感性之间有弱相关性,在亚组分析中发现rs763780与CD的病变范围和UC的发病年龄有关.IL-17A rs2275913基因多态性与UC疾病严重程度呈负相关.     

上海地区幽门螺杆菌cagA基因3′区和VacA基因的多态性分析及其临床意义

目的:探讨上海地区人群中幽门螺杆菌(H.Pylori)cagA基因3′区和vacA基因的多态性及其临床意义.方法:99株H.pylori菌株分离自17例慢性浅表性胃炎(CSG)、21例慢性萎缩性胃炎(CAG)、19例胃溃疡(GU)、23例十二指肠溃疡(DU)和19例胃癌(GC)患者.用聚合酶链反应(PCR)技术对H.Pylori菌株的cagA基因3′区和vacA基因信号序列及中间区等位基因进行扩增和检测.结果:99株H.Pylori菌株中84株(84.8%)cagA基因阳性,其3′区产物大小均约650 bp,属A型.vacA基因信号序列仅检出s1a型,见于从94.1%(16/17)的CSG、95.2%(20/21)的CAG、89.5%(17/19)的GU、87.0%(20/23)的DU和89.5%(17/19)的GC患者中分离的菌株(P=0.87);中间区等位基因仅检出m2型,见于从70.6%(12/17)的CSG、71.4%(15/21)的CAG、63.2%(12/19)的GU、73.9%(17/23)的DU和57.9%(11/19)的GC患者中分离的菌株(P=0.72).结论:上海地区人群中H.Pylori菌株的cagA基因3′区相对保守;绝大多数vacA基因属s1a/m2型.本研究结果不支持这些基因的多态性与H.Pylori感染临床结局相关的观点.     

IL-17基因多态性与新疆地区中老年人群骨性关节炎易感性的关系

目的探讨白细胞介素(IL)-17基因多态性与新疆地区中老年人群骨性关节炎易感性的关系。方法选取行全膝关节置换术的膝关节骨性关节炎患者400例为骨性关节炎组;另取年龄、性别相匹配的健康志愿者260例为健康对照组。采集两组受试者外周静脉血并提取DNA,采用等位基因聚合酶链反应-单链构型多态性(PCR-sscp)检测IL-17A G-289A基因rs3386824位点和IL-17F T-8599基因rs874891位点单核苷酸多态性,对组间有明显差异的基因型计算OR值和95%可信区间(CI)。结果 IL-17A G-289A(rs3386824)基因分布频率方面,骨性关节炎组与健康对照组之间差异有统计学意义(P0.01);其中各基因型OR值分析显示,携带G等位基因(G/A、G/G)的受试者骨性关节炎发生风险明显高于A/A基因型者。对基因频率在人群中分布情况进行H-W定律检验显示,骨性关节炎组基因遗传不平衡(P=0.000),健康对照组基因遗传平衡(P=0.358)。骨性关节炎组与健康对照组不同性别受试者的IL-17A G-289A基因多态性分布差异无统计学意义(P0.05)。低年龄组(≤65岁)中骨性关节炎组与健康对照组IL-17A G-289A基因型分布差异无统计学意义(P0.05);高年龄组中(65岁)骨性关节炎组与健康对照组基因型分布差异有统计学意义(P0.05);OR值分析显示,高年龄组人群携带IL-17A G-289A基因增加骨性关节炎发病率。IL-17F T-8599(rs874891)基因分布频率方面,骨性关节炎组各基因型及其等位基因分布频率与健康对照组之间差异均无统计学意义(P0.05)。结论新疆地区老年人群中,IL-17A G-289A多态性与骨性关节炎易感性相关,阳性位点rs3386824等位基因G/A、G/G是其高风险因素,A/A为低风险因素。     

WT1+17AA异构体在急性髓系白血病中的表达特点

WT1基因定位于11p13,可通过选择性剪接编码4种异构体:WT1A(-17AA/-KTS)、WT1B(+17AA/-KTS)、WT1C(-17AA/+KTS)、WT1D(+17AA/+KTS)[1].许多文献证实80%～90%的急性白血病无论型别均过表达野生型WT1基因[2],新近研究表明WT1基因调节细胞周期和凋亡途径,WT1+17AA异构体在内源性凋亡途径中在线粒体上游某些位点起着抗凋亡作用[3].了解不同亚型、不同病程阶段的急性髓系白血病(AML)中WT1基因及其异构体比例对于AML的发病机制的阐释非常重要.     

霍乱弧菌基因表达分析中内参基因的选择

目的确定不同实验条件下基因表达分析中的稳定内参基因。方法以霍乱弧菌O1群El Tor菌株为研究对象,利用qRT-PCR方法比较不同pH值(pH 8.0、pH 5.5)以及不同温度(37℃、30℃)等多种生理、外界环境模拟培养条件下,thyA、recA、rpoA、gyrB、16SrRNA以及VCA0862 6个候选内参基因的表达水平,利用geNorm软件评价其稳定性。结果不同培养条件下,6个候选内参基因表达水平存在差异。不同pH值条件下最佳基因是recA;不同温度条件下最佳基因是gyrB;不同pH值及温度综合评价时,最佳基因是recA。结论本研究评价和提出了细菌基因表达分析中内参基因筛选的重要性,不同实验条件下最稳定内参基因是不同的,针对不同条件下的基因转录定量分析,应分别对内参基因稳定性进行评价并选择最稳定基因。     

Genetic susceptibility for breast cancer: how many more genes to be found?

Today, breast cancer is the most commonly occurring cancer among women. It accounts for 22% of all female cancers and the estimated annual incidence of breast cancer worldwide is about one million cases. Many risk factors have been identified but a positive family history remains among the most important ones established for breast cancer, with first-degree relatives of patients having an approximately two-fold elevated risk. It is currently estimated that approximately 20-25% of this risk is explained by known breast cancer susceptibility genes, mostly those conferring high risks, such as BRCA1 and BRCA2. However, these genes explain less than 5% of the total breast cancer incidence, even though several studies have suggested that the proportion of breast cancer that can be attributed to a genetic factor may be as high as 30%. It is thus likely that there are still breast cancer susceptibility genes to be found. It is presently not known how many such genes there still are, nor how many will fall into the class of rare high-risk (e.g. BRCAx) or of common low-risk susceptibility genes, nor if and how these factors interact with each other to cause susceptibility (a polygenic model). In this review we will address this question and discuss the different undertaken approaches used in identifying new breast cancer susceptibility genes, such as (genome-wide) linkage analysis, CGH, LOH, association studies and global gene expression analysis.     

Loss of all ndh genes as determined by sequencing the entire chloroplast genome of the black pine Pinus thunbergii.

The complete nucleotide sequence (119,707 bp) of the black pine (Pinus thunbergii) chloroplast genome has been determined. It contains 4 rRNA genes and 32 tRNA genes. To our knowledge, the tRNAPro (GGG) gene has not been found in any other chloroplast genome analyzed. Sixty-one genes encoding proteins and 11 conserved open reading frames are also found. Extensive rearrangements are apparent in the chloroplast genome relative to those of other land plants. The most striking feature is the loss of all 11 functional genes (ndh genes) for subunits of a putative NADH dehydrogenase that are found in the chloroplast genomes of angiosperms and a bryophyte. Four ndh genes were completely lost and the other 7 genes remain as obvious pseudogenes. This unexpected finding raises the possibility that all ndh genes have been transferred to the nucleus or that an NADH dehydrogenase is not essential in black pine chloroplasts.     

MYH and colorectal cancer. A significant advance?

Colorectal cancer is the second most common neoplasm and the second most frequent cause of cancer-related deaths in Spain. This neoplasm has an important genetic component, although relatively few of the genes involved in its hereditary or familial forms have been identified. One of the latest genes to be identified is the MYH gene. Colorectal polyposis associated with mutations in the MYH gene is an autosomal recessive syndrome characterized by the development of colorectal adenomas and cancer. It is the first disease predisposing to cancer to be associated with defects in base excision repair.     

Determinants of bleeding severity in von Willebrand disease

von Willebrand disease (VWD) is one of the most common bleeding disorders. It is caused by abnormalities in the von Willebrand factor (VWF) protein, and is characterized by incomplete penetrance and variable expressivity. VWF levels vary widely in the population. The best-characterized human genetic modifier of VWF is the ABO blood group. Patients with VWD show considerable variation in bleeding tendency even within the same family, independently of VWF levels. It is possible that several modifier genes influence the phenotype. Variants of genes that encode for platelet receptors as well as those that encode for clotting factor levels have been proposed as modifiers. It is hoped that new clinical-genetic studies will shed light on these issues and help practitioners to determine the population at risk for bleeding.     

A MODEL RELATING GENE REPLICAS AND GENE REPRESSION TO PHENOTYPIC EXPRESSION AND VARIABILITY

It is suggested that the development of a dominant character in higher organisms starts with the activation of a major gene. This gene replicates; the number of replicas is controlled by a second gene or set of genes, which also ensure that the most suitable allele, if more than one is present, makes the replicas. The major gene replicas then make messenger RNA and are reinforced in this by minor genes. The joint product of major gene replicas and minor genes activates a fourth gene or set of genes which produce a repressor that damps down the activity of the major gene replicas. The evidence for this scheme, which comes from studies of selection experiments in populations, is summarized and the evidence from studies of DNA and RNA metabolism is referred to in this paper.     

Developmental switches in reiterated genes may reduce the rate of age changes in DNA

The possible role of the redundancy of genetic information in the regulation of the ageing rate has been discussed in several works. However, it was shown recently that the gene reiteration in most cases is represented by families of similar, but not identical genes. Their expression usually related to the different stages of development and when “early” embryonic or fetal genes are active, the “late” or adult genes are repressed. It is known that the DNA repair needs double stranded structure of DNA which is usual for inactive genes. Genes which are being transcribed and active are repressed by unwound, relaxed DNA which is less protected by the DNA repair enzymes. Aging of genetic information in somatic cells can be, therefore, considered as stage specific and alterations of “early” embryonic and fetal genes do not constitute the genetic load which influences the ageing rate of differentiated cells.     

The role of human and mouse Y chromosome genes in male infertility

It was suggested by Ronald Fisher in 1931 that genes involved in benefit to the male (including spermatogenesis genes) would accumulate on the Y chromosome. The analysis of mouse Y chromosome deletions and the discovery of microdeletions of the human Y chromosome associated with diverse defective spermatogenic phenotypes has revealed the presence of intervals containing one or more genes controlling male germ cell differentiation. These intervals have been mapped, cloned and examined in detail for functional genes. This review discusses the genes mapping to critical spermatogenesis intervals and the evidence indicating which are the most likely candidates underlying Y-linked male infertility.