同型半胱氨酸代谢酶基因多态性与深静脉血栓的相关性研究

目的探讨亚甲基四氢叶酸还原酶（methylenetetrahydrofolate reductase，MTHFR）基因C677T、甲硫氨酸合成酶（methionine synthase，MS）基因A2756G和胱硫醚β-合成酶（cystathionine β-synthase，CBS）基因844ins68这3种基因突变在深静脉血栓发病中的意义。方法应用聚合酶链反应-限制性片段长度多态性方法对103例深静脉血栓患者和250名健康对照者进行MTHFR C677T、MS A2756G和CBS 844ins68基因多态性的分析，并进行基因型及等位基因频率的计数。对MTHFR C677T和MS A2756G两位点进行单倍型分析。结果MTHFR C677T TT基因型在深静脉血栓组的分布频率（27．2％）高于对照组（17．2％），经χ^2检验差异有统计学意义（P〈0．05）。MS A2756G AG基因型在深静脉血栓组的分布频率（9．7％）低于对照组（19．2％），经χ^2检验差异有统计学意义（P〈0．05）。单倍型分析显示病例组中677T-2756A单倍型频率明显高于对照组（P〈0．05），677C-2756A单倍型频率明显低于对照组（P〈0．05）。CBS 844ins68基因型在两组的分布频率差异无统计学意义。结论MTHFR C677T多态性中TT基因型可能是深静脉血栓形成的一个遗传风险因子，MS 2756 AG基因型可能会减少深静脉血栓的发生。677T-2756A单倍型可能是静脉血栓的危险因素，677C-2756A单倍型可能是静脉血栓的保护因素。CBS 844ins68基因突变可能存在种族或地域的差异。     

贵州苗族、侗族、布依族人群白介素10基因-592与-819位点的多态性研究

目的 研究中国贵州世居少数民族苗族、侗族与布依族人群中白介素10 (IL-10)基因启动子区-592与-819位点的多态性,为进一步研究其与疾病的相关性提供依据.方法 对上述人群采用TaqMan-MGB探针实时荧光聚合酶链反应SNP分型技术分析IL-10-592与IL-10-819位点多态性.结果 IL-10-819基因型频率在贵州苗族与侗族、苗族与布依族中的分布差异有统计学意义(P＜0.05),而在侗族与布依族之间分布差异无统计学意义(P＞0.05),IL-10-819(C/T)位点在贵州苗族群体中具有较高的突变率.IL-10-592基因型频率在贵州苗族与侗族、苗族与布依族之间分布差异有统计学意义(P＜0.05),在贵州侗族与布依族之间分布差异无统计学意义(P＞0.05),贵州苗族群体中IL-10-592位点T等位基因频率远高于侗族与布依族群体.贵州苗族、侗族、布依族IL-10-592位点与IL-10-819位点的多态分布与希腊及巴西人群分布差异无统计学意义(P＞0.05),而与中国广州及台湾汉族人、韩国人、加拿大人群的分布差异有统计学意义(P＜0.05),IL-10-592 A与IL-10-819 T突变频率显著低于中国广州及台湾汉族人和韩国人群的突变频率,但又显著高于加拿大人群的IL-10-592 A与IL-10-819 T的突变频率.结论 IL-10-819与IL-10-592多态性位点在贵州世居少数民族苗族、侗族与布依族人群中有着不同的分布,而IL-10-819与IL-10-592位点在不同种族、地域的群体中分布亦有显著的差异.     

叶酸代谢相关基因多态性及血浆同型半胱氨酸与唐氏综合征关系研究

目的研究叶酸代谢相关的亚甲基四氢叶酸还原酶(methylenetetrahydrofolate reductase,MTH-FR)基因多态性与唐氏综合征(Down syndrome,DS)发生的关系。方法选择100例生育过DS患儿的汉族母亲及100名相匹配的正常对照组母亲,PCR-限制性片段长度多态性方法检测MTHFR677C/T的基因型,化学发光法检测血浆中同型半胱氨酸(homocysteine,HCY)的水平。结果病例组MTHFR677T等位基因的频率较对照组增高,差异有统计学意义(P=0.002);杂合基因型CT的比值比为2.12(95%CI:1.14～3.94);而纯合基因型TT的比值比为3.43(95%CI:1.41～8.36)。平均血浆HCY浓度在病例组[(9.04±3.85)μmol/L]较对照组[(6.53±2.06)μmol/L]增高,差异有统计学意义(P<0.01)。MTHFR677位点一个和(或)两个等位基因C→T的变异,不论在病例组还是对照组均可引起HCY水平的显著增加(P<0.01)。同为MTHFR677CC基因型,病例组中的血浆HCY浓度仍较对照组增高(P<0.01),这种增加不依赖于MTHFR的基因型。结论血浆HCY和叶酸代谢相关基因的遗传多态性是汉族妇女生育DS患儿的危险因素。     

临沂市汉族女性MTHFR和MZRR基因多态性分布及其与同型半胱氨酸水平的相关性

目的 分析山东省临沂市汉族女性亚甲基四氢叶酸还原酶(methylenetetrahydrofolate reductase,MTHFR)677C/T、1298A/C及甲硫氨酸合成酶还原酶(methionine synthase reductase,MTRR)66A/G基因多态性的分布特征,及其与同型半胱氨酸(homocysteine,Hcy)水平的相关性.方法 采用横断面调查研究方法,以临沂市825名汉族女性为研究对象,采集口腔黏膜上皮细胞,提取基因组DNA,采用Taqman-MGB技术进行MTHFR和MTRR基因多态性检测.统计分析基因多态性的分布特征,并与其他地区(山东省潍坊市、河南省郑州市、四川省德阳市及海南省)的数据进行比较.采用酶转换法检测281名研究对象的血浆Hcy浓度,根据MTHFR基因多态性将其分为MTHFR酶活性基本正常组和显著降低组,分析Hcy水平与MTHFR酶活性的相关性.结果 (1)临沂市汉族女性的MTHFR677CC、CT、TT的基因型频率分别为16.7%、48.3%和35.0%,TT纯合突变高于四川德阳和海南地区(P<0.01).MTHFR 1298AA、AC、CC的基因型频率分别为76.0%、21.6%和2.4%,CC纯合突变基因型频率低于四川德阳和海南地区(P<0.01).MTRR 66AA、AG、GG的基因型频率分别为54.7%、39.4%和5.9%,GG纯合突变基因型频率低于海南地区(P<0.01).(2)MTHFR酶活性显著降低组的Hcy水平高于酶活性基本正常组,差异有统计学意义(P<0.05).结论 (1)临沂市汉族女性有不同于其他地区的MTHFR和M7RR基因多态性分布特征.(2)MTHFR基因多态性导致的酶活性降低是Hcy水平升高的风险因素.     

阿尔茨海默病患者同型半胱氨酸代谢相关酶基因突变频度的研究

目的　探讨胱硫醚β合成酶 (CBS)基因 84 4ins6 8、甲硫氨酸合成酶 (MS)基因A2 75 6G、亚甲基四氢叶酸还原酶 (MTHFR)基因C6 77T三种同型半胱氨酸代谢相关酶基因突变在阿尔茨海默病 (AD)发病中的意义 .方法　PCR扩增AD 6 6例及 14 3例对照者的CBS、MS、MTHFR基因突变点 ,直接或经限制性内切酶消化后行凝胶电泳确定其基因型 .结果　AD病人MTHFR基因中 ,基因型C/T占 5 6 .0 6 % ,明显高于对照组 (p <0 .0 1) ,C/C明显低于对照组 (p <0 .0 1) ,T/T与对照组无明显差异 (p>0 .0 5 ) .AD病人中MTHFR基因等位基因C的频率相对危险率 (RR) ,T的频率与对照组的差异有显著性 (p<0 .0 5 ) .CBS 84 4ins6 8、MSA2 75 6G各种基因型频率在AD组与对照组之间无差异 .结论　AD病人中MTHFR T频率明显高于正常人 ;而MTHFR C频率则明显低于正常人 ,而CBS 84 4ins6 8、MSA2 75 6G突变可能不足以构成阿尔茨海默病的独立遗传性危险因子     

阿尔茨海默病患者同型半胱氨酸代谢相关酶基因突变频度的研究

目的探讨胱硫醚β合成酶(CBS)基因844ins68、甲硫氨酸合成酶(M S)基因A2756G、亚甲基四氢叶酸还原酶(MTHFR)基因C677T三种同型半胱氨酸代谢相关酶基因突变在阿尔茨海默病(AD)发病中的意义.方法 PCR扩增AD 66例及143例对照者的CBS、MS、MTHFR基因突变点,直接或经限制性内切酶消化后行凝胶电泳确定其基因型.结果 AD病人MTHFR基因中,基因型C/T占56.06%,明显高于对照组(p<0.01),C/C明显低于对照组(p <0.01),T/T与对照组无明显差异(p>0.05). AD病人中MTHFR基因等位基因C的频率相对危险率(RR),T的频率与对照组的差异有显著性(p<0 .05).CBS 844ins68、MS A2756G各种基因型频率在AD组与对照组之间无差异 .结论 AD病人中MTHFR*T频率明显高于正常人;而MTHF R *C频率则明显低于正常人,而CBS 844ins68、MS A2756G突变可能不足以构成阿尔茨海默病的独立遗传性危险因子.     

母亲叶酸代谢相关基因多态性与唐氏综合征发生的关系

目的研究叶酸代谢相关基因多态性在浙南地区汉族妇女中的分布,探讨其与唐氏综合征(Down’s Syn-drome,DS)发生的关系。方法对84例已生育DS患儿的母亲(观察组)和120例生育过正常儿童的母亲(对照组)采用PCR扩增及DNA测序法检测亚甲基四氢叶酸还原酶(MTHFR)基因C677T、A1298C位点;甲硫氨酸合成酶(MTR)基因A2756G位点单核苷酸多态性。结果 MTHFR 677 T基因及CT、TT基因型、MTHFR 1298 C基因及AC、CC基因型、MTR 2756 G基因及AG基因型频率观察组与对照组比较均无统计学意义(P>0.05)。三个位点基因型频率联合分析两组也不存在统计学意义(OR=0.692,P>0.05)。结论浙南地区汉族妇女MTHFR C677T、FTHFR A1298C、MTR A2756G基因型不是DS发生的风险因素;三个基因型的联合频率也未见增加DS发生的风险。     

同型半胱氨酸代谢酶基因突变多态性与妊娠高血压综合征遗传易感性研究

目的探讨同型半胱氨酸代谢酶—甲基四氢叶酸还原酶(MTHFR)、蛋氨酸合成酶(MS)和胱硫醚-β合成酶(CBβS)基因多态性在妊娠高血压综合征(妊高征)发病中的作用地位。方法荧光偏振免疫分析法测定血浆总Hcy浓度;聚合酶链反应-限制性片段长度多态性技术(PCR-RFLP)检测MTHFRC677T、MSA2756G、MTRRA66G和CBβS844ins68基因多态性。结果病例组MTHFRC677TC/T基因型频率显著高于正常对照组,总的突变T等位基因频率显著高于对照组(P<0.05);病例组MS野生型A等位基因频率明显高于对照组,而突变型G等位基因频率显著低于对照组。结论MTHFRC677T基因突变是妊高征发生的遗传风险因素;MSA2756多态性改变是妊高征的保护因子。二者均可作为妊高征预后的检测指标。     

血浆同型半胱氨酸水平及其代谢酶基因多态性与脑梗死的相关性研究

目的 通过探讨同型半胱氨酸(homocysteinemia,Hcy)及其主要代谢酶突变基因与脑梗死的关系,明确遗传因素与脑梗死发病的关联性,为指导临床提供理论依据.方法 选择脑梗死患者与正常健康者各60例分别为脑梗死组、正常对照组.采用高效液相色谱法(high-performance liquid chromatography,HPLC)测定血浆Hcy水平,并应用聚合酶链式反应-限制性片段长度多态分析技术(polymerase chain reaction-restriction fragment length polymorphism,PCR-RFLP)测定基因表型.结果 正常对照组与脑梗死组比较,Hcy水平明显偏高(P＜0.01),患者组有无高血压病史、高血脂病史、糖尿病病史,Hcy水平差异无统计学意义(P＞0.01).脑梗死组亚甲基四氢叶酸还原酶(methylenetetralydrofolate,MTHFR)基因TT基因型与正常组比较差异有统计学意义(P＜0.01),T等位基因频率明显高于正常对照组(P＜0.01).MTHFR C677T基因型和等位基因频率分布与正常组比较差异均有统计学意义(P＜0.01).MTHFR基因C677T纯合子基因型Hcy水平显著高于野生型(P＜0.01).丝氨酸在胱硫醚β合成酶(cystathionineβ-synthase,CBS)基因T27796C纯合子基因型血浆Hcy水平与杂合子基因型比较差异有统计学意义(P＜0.01),显著高于野生型(P＜0.01).Logistic回归分析脑梗死血浆Hcy水平和MTHFR C677T纯合子基因型关系密切.结论 Hcy水平与脑梗死的发病有一定关联性,可能是该病发生的一个独立危险因素.MTHFR基因C677T位点纯合子突变、CBS基因T27796C位点纯合子突变均可致血浆Hcy水平增高,可能是脑梗死发生的遗传因素.     

贵州省荔波县汉族和布依族女性MTHFR与MTRR多态性的分布

目的 针对贵州省荔波县汉族和布依族女性开展分子流行病学调查,研究叶酸代谢关键酶亚甲基四氢叶酸还原酶(MTHFR)和甲硫氨酸合成酶还原酶(MTRR)的基因多态性分布.方法 以在荔波县人民医院进行围孕期保健的1342名健康女性为研究对象,其中汉族236人、布依族1106人.采集口腔黏膜上皮脱落细胞,抽提基因组DNA,使用荧...     

贵州苗族、布依族、侗族人群线粒体DNA 9 bp序列缺失频率分析

目的 调查贵州苗族、布依族、侗族人群线粒体DNA细胞色素氧化酶Ⅱ和t RNALys基因间小非编码Ⅴ区串联重复序列9 bp的缺失频率.方法 采用聚合酶链反应-聚丙烯酰胺凝胶方法及DNA序列分析法对105名苗族、97名布依族、102名侗族的男性个体线粒体DNA的9 bp缺失多态频率进行分析.结果 在304名男性中仅发现标准型和短型(即9 bp缺失)两种多态,缺失频率为23.0％(70/304).其中苗族缺失频率为28.6％(30/105)、布依族为26.8％(26/97)、侗族为13.7％(14/102).三者之间的差异具有统计学意义(P＜0.05).结论 贵州苗族、布依族、侗族人群线粒体DNA 9 bp缺失基因频率均较高,三者之间差异有统计学意义.     

贵州苗、布依、侗、水四个少数民族Rh血型分布调查分析

目的了解贵州主要的4个少数民族中Rh血型分布及基因频率，为指导Rh溶血症防治提供科学依据。方法随机整群抽取贵州苗、布依、侗、水4个民族的无关个体进行Rh血型鉴定和分析。结果共筛查4个少数民族15992人，汉族对照4851人。发现Rh（D）阴性个体51名，苗族d基因频率0．0474、Rh阴性率为0．22％。布依族d基因频率0．0602、Rh阴性率为0．36％。侗族d基因频率0．0378、Rh阴性率为0．14％。水族d基因频率0．0307、Rh阴性率为0．09％。汉族（对照组）d基因频率0．0574、Rh阴性率为0．33％。4个少数民族均有表现型CCDee型最高（52．47％～59．66％）的共同特征。同时4个民族的基因型频率均以CDe最高，分别为苗族：0．7244、布依族：0．7389、侗族：0．7410、水族：0．7743。结论贵州4个少数民族苗、布依、侗、水族Rh血型分布特征，与国内南方少数民族相似。苗、侗、水族Rh阴性比例都低于汉族（0．33％），仅布依族Rh阴性率（0．36％）接近并略高于汉族。因此，贵州少数民族中Rh新生儿溶血症发生率不高。     

贵州侗族、苗族和汉族人群乙型肝炎病毒基因型分布

目的　了解贵州侗、苗、汉族HBV感染者的基因型。方法　比较 12 7株各基因型HBV全序列S基因核苷酸序列 ,用DNA分析软件筛选出 3个限制性内切酶。设计 3条HBVS区引物并进行聚合酶链反应扩增 ,产物经MboⅠ、BstNⅠ或BsmAⅠ酶切 ,分析酶切产物电泳图谱 ,建立区分HBV(A～F)基因型的方法。对贵州 16 6份侗、苗、汉族HBV感染者血清进行基因分型 ,5份PCR产物直接测序验证分型方法的准确、可靠。结果　S基因PCR RFLP分型结果准确 ,5份酶切鉴定结果经测序证实。 16 6份标本中 ,B基因型 138份 (83 13% ) ,C型 2 8份 (16 87% ) ,未发现B、C以外的其他基因型。侗族的 4 8例中 ,4 7例为B型 (97 92 % ) ,1例C型 (2 0 8% ) ,苗族的 5 2例中 ,4 9例为B型(94 2 3% ) ,3例C型 (5 77% ) ;6 6例汉族也以B基因为主 (6 3 6 4 % ,4 2 6 6 ) ,但C型有 2 4例 (36 36 % ) ,与侗、苗族HBV感染者相比 ,差异有显著意义 (χ2 =35 0 5 88,P <0 0 0 5 )。结论　贵州地区HBV基因型由B、C 2型构成 ,且以B基因型为主。汉族患者C型较多 ,而侗、苗族患者中B型是占绝对优势的基因型。     

Polymorphisms in folate and homocysteine metabolizing genes and chromosome damage in mothers of Down syndrome children

We recently observed an association between combinations of polymorphisms in the methylenetetrahydrofolate reductase (MTHFR 677C > T or 1298A > C) and reduced folate carrier (RFC-1 80G > A) genes and the risk of a Down syndrome (DS) pregnancy in young Italian women. Others have observed an association between a methionine synthase (MTR 2756A > G) gene polymorphism and the risk of a DS offspring in Italy. Moreover, in a separate study, we observed an increased frequency of both binucleated micronucleated cells (BNMN) and chromosome malsegregation events in peripheral lymphocytes of mothers of DS individuals aged less than 35 years at conception (MDS) in respect to controls. The aim of the present study was to evaluate chromosome damage, measured by means of the micronucleus assay, in peripheral lymphocytes of a group of women (n = 34) who had a DS child in young age (<35 years) and in a control group (n = 35), and to correlate them with MTHFR 677C > T and 1298A > C, RFC-1 80G > A and MTR 2756A > G polymorphisms. We observed an increased frequency of BNMN in the MDS group compared to the control group (17.13 +/- 8.31 per thousand vs. 10.28 +/- 4.53 per thousand; P < 0.001), and, in the general population, a correlation between years of age and BNMN frequency (P = 0.05). A significant correlation between the frequency of BNMN and the MTHFR 677C > T polymorphism (P = 0.038) was also found. Present results indicate that MDS are more prone to chromosome damage than control mothers; moreover the contribution of folate and homocysteine metabolizing gene polymorphisms seems to have an effect on the baseline frequency of BNMN lymphocytes.     

Polymorphisms in the methylenetetrahydrofolate reductase and methionine synthase reductase genes and homocysteine levels in Brazilian children

Hyperhomocysteinemia is a risk factor for thrombosis, and methylenetetrahydrofolate reductase (MTHFR) and methionine synthase reductase (MTRR) polymorphisms, folate, and B12 levels could contribute to plasma homocysteine (Hcy) variation. Although well established in adults, few studies have been performed in childhood. In this study, we investigated association of polymorphisms C677T and A1298C in the MTHFR gene and A66G in the MTRR gene with Hcy levels in children. These polymorphisms, as well as Hcy, folate, and vitamin B12 levels were investigated in 220 normal children with ages ranging from 1 to 8 years. Plasma Hcy, folate, and vitamin B12 levels were normal in all children. None of the polymorphisms could be considered an independent risk factor for hyperhomocysteinemia during childhood. The median Hcy levels in 37 children (17%) doubly heterozygous for C677T and A1298C mutations in the MTHFR gene were not different from the other genotypes. However, the association of the different genotypes with Hcy, folate, and vitamin B12 levels demonstrated significant P-values. The folate levels demonstrated a statistically significant decrease (P = 0.0477) from the C677T mutation in the MTHFR gene (TT genotype) when compared to the other groups. Folate was the only independent risk factor for hyperhomocysteinemia. Thus, monitoring the concentrations of folate would be more helpful for evaluating hyperhomocysteinemia and for preventing cardiovascular disease.     

湘西侗族、苗族青年手的形态学研究

目的了解湘西侗族、苗族18²5岁青年人手的形态学参数,为手外科损伤修复、机械装备、工具制造及手套设计提供形态学基础,丰富形态学资料。方法对400例在校大学生的左、右手进行16项活体测量,并对获取的资料进行统计学分析。结果同民族、不同性别间男、女生手长、手指长、手掌宽、手最大宽存在差异,且与其他地区比较手指长度有差异。但在同性别、不同民族间手的形态学参数无差异。结论湘西青年人的手短小,有地区差异。     

Polymorphisms in eosinophil pathway genes, asthma and atopy

BACKGROUND: Eosinophilic inflammation is considered to play an important role in the development as well as in the perpetuation of asthma. As eosinophil production and survival is under genetic control we investigated whether polymorphisms in eosinophil regulation pathway genes (IL-3, IL-5, GM-CSF and their respective enhancers and receptors) may influence the development of atopic diseases. METHODS: In two large study populations of children, the German part of the International Study of Asthma and Allergy in Childhood (ISAAC II) and the German Multicentre Atopy Study (MAS), 3099 and 824 children, seven polymorphisms previously associated with the development of atopic diseases were genotyped: two in and around the GM-CSF gene (Ile117Thr and T3085G), one in IL-3 (Pro27Ser), in IL-5 (C-746T), and in the IL-5 high affinity receptor chain IL-5R (G-80A) and two in the common receptor chain CSFR2b for IL-3, IL-5, and GM-CSF (Asp312Asn and Glu249Gln). Statistical analyses were performed using chi-squared tests and variance analyses. Gene by gene interactions were evaluated in logistic regression models. RESULTS: The T allele at position -746 in the IL-5 gene was significantly protective for atopy in the ISAAC II population (P = 0.006). Furthermore, the risk for atopic asthma was decreased in carriers of the T allele (P = 0.036) and evidence for interaction with the enhancer polymorphism 3085 bp 3' of GM-CSF was detected. CONCLUSIONS: IL-5 C-746T influenced atopic outcomes and showed evidence for gene by gene interaction. No significant associations were found with all other tested polymorphisms in the eosinophil regulation pathway after correction for multiple testing.     

Polymorphisms in one-carbon metabolism pathway genes and risk for bladder cancer in a Tunisian population

Cigarette smoking is the most important risk factor for bladder cancer. Moreover, epidemiologic studies have implicated several genetic variations interfering with methyl group metabolisms in susceptibility for a variety of cancers. Examples of these variations can be found in genes of the folate metabolic pathway, which is crucial in the provision of methyl groups for DNA, RNA, and protein methylation, as well as in purine and pyrimidine synthesis. We conducted a case–control study to examine the relationship between the methylenetetrahydrofolate reductase (MTHFR C677 T and MTHFR A1298C), methionine synthase (5-methyltetrahydrofolate-homocysteine methyltransferase, MTR A2756 G), methionine synthase reductase (5-methyltetrahydrofolate-homocysteine methyltransferase reductase, MTRR A66 G and MTRR C524 T), and thymidylate synthase (TYMS 2R→3R and G/C) genotypes and the risk for bladder cancer in a Tunisian population. The isolated MTHFR 677*T, MTRR 66*G and MTRR 524*T variants did not appear to influence bladder cancer susceptibility. The 3R*C/3R*C genotype for the TYMS gene appears to be a protective factor against bladder cancer development (P=0.0001; OR=0.12; 95% CI=0.03–0.40). However, patients heterozygous for MTHFR A1298C or MTR A2756 G genotypes have 1.62- and 2.13-fold higher risk, respectively, of developing bladder cancer. Moreover, the combined study of MTHFR 1298*C and MTR 2756*G variants with either or both MTRR 66GG and TYMS 3R*G/3R*G genotypes suggests a cumulative effect. Finally, this study evidenced that interaction between gene variations involved in folate metabolism and risk of bladder cancer increased dramatically among smokers.