胱硫醚-β合成酶基因多态性与颅内动脉瘤的关系

目的探讨胱硫醚-β合成酶基因CBS 844ins 68基因多态性与颅内动脉瘤的关系。方法运用多聚酶链反应技术检测76例颅内动脉瘤及143例正常人CBS 844ins 68基因多态性。结果 颅内动脉瘤组CBS 844ins 68 D/D、D/I、I/I基因型频率(%)分别为78.95、19.74、1.31,对照组分别为78.32、18.88、2.8,CBS 844ins 68各种基因型频率在患者组与正常对照组之间的无显著性差异(p>0.05)。结论胱硫醚-β合成酶多态性与颅内动脉瘤无明显相关。     

5,10-亚甲基四氢叶酸还原酶多态性和神经管畸形的病例对照研究

目的探讨北方乡村妇女亚甲基四氢叶酸还原酶(MTHFR)基因多态性与神经管畸形的关系.方法用聚合酶链反应-限制性片段的多态性(PCR-RFLP)技术,检测20例生育神经管畸形患儿(NTDs)的妇女及76例农村和73例城市正常出生儿母亲的MTHFR基因多态性.结果 MTHFR基因第677位核苷酸呈多态性,可分为三种类型:C/C、C/T、T/T.病例组三种基因突变频率:C/C,5%;C/T,50%;T/T,45%.城市对照组分别为:C/C,28.8%;C/T,54.8%;T/T,16.4%.乡村对照组分别为:C/C,34.2%;C/T,46.1%;T/T,19.7%.病例组T/T基因突变频率显著高于对照组,而城乡正常妇女T/T基因突变频率基本一致.结论提示母亲MTHFR基因突变与生育NTDs患儿有相关性.     

MTHFR基因多态性与自然流产的关系

目的探讨亚甲基四氢叶酸还原酶(MTHFR)基因C677T多态性与自然流产的相关性。方法选取2015年1-7月该院产前诊断中心既往有自然流产妇女289例为研究对象,其中自然流产1次或2次者210例为流产组1,流产≥3次者79例为流产组2;随机选取同期正常妇女280例为对照组。采集静脉血,提取基因组DNA,采用基因测序技术分析MTHFR基因中C677T的分型。结果流产组1中MTHFR C677T基因型和等位基因分布同对照组比较,差异无统计学意义(P0.05);流产组2中MTHFR C677T基因型和等位基因分布同对照组比较,差异有统计学意义(P0.05)。结论 MTHFR基因多态性与非复发性流产相关性不显著,同复发性流产组相关性显著。     

MTHFR基因多态性与先兆流产和复发性流产的关系

目的探讨5,10-亚甲基四氢叶酸还原酶(MTHFR)基因C677T和A1298C位点多态性与先兆流产和复发性流产的关系。方法选取2016年7月-2017年7月在台州市中心医院就诊的135例先兆流产患者和108例复发性流产患者分别为先兆流产组和复发性流产组,选取于同院接受健康查体的140例育龄期健康女性为对照组。采用荧光定量PCR技术检测3组MTHFR基因C677T和A1298C位点的多态性。结果先兆流产组与对照组MTHFR基因C677T位点CC、CT、TT基因型频率比较差异无统计学意义(P0. 05); TT基因型频率在复发性流产组中显著升高,而CC基因型频率在复发性流产组中显著降低(P0. 05)。复发性流产组MTHFR基因C677T位点T等位基因频率显著高于对照组(P0. 05),相对于纯合未突变等位基因C的相对危险度OR=1. 816,95%CI为1. 258～2. 622;先兆流产组与对照组T等位基因频率比较差异无统计学意义(P0. 05)。与对照组比较,先兆流产组、复发性流产组MTHFR基因A1298C位点AA、AC、CC基因型频率比较差异均无统计学意义(均P0. 05);先兆流产组及复发性流产组C等位基因频率与对照组相比差异均无统计学意义(均P 0. 05)。结论 MTHFR基因C677T位点C/T变异可能是台州地区复发性流产的因素之一,MTHFR基因A1298C位点多态性与先兆流产和复发性流产的发生无明显相关性。     

亚甲基四氢叶酸还原酶和纤溶酶原激活剂抑制物1基因多态性与结直肠癌术后下肢深静脉血栓形成的关系

目的分析亚甲基四氢叶酸还原酶(MTHFR)和纤溶酶原激活剂抑制物1(PAI-1)基因多态性与结直肠癌术后下肢深静脉血栓(DVT)形成的关系。方法回顾性分析2020年2月至2023年2月于张家口市第一医院行手术治疗的100例结直肠癌患者的临床资料, 根据术后有无发生下肢DVT分为DVT组20例和非DVT组80例, 采用聚合酶链反应方法检测MTHFR基因C677T位点多态性和PAI-1启动子4G/5G基因多态性, 采用Logistic回归分析MTHFR基因C677T位点基因多态性和PAI-1启动子4G/5G基因多态性与结直肠癌术后下肢DVT的关系。结果 DVT组MTHFR基因C677T位点TT基因频率及T等位基因频率高于非DVT组[65.00%(13/20)比25.00%(20/80)和80.00%(32/40)比38.75%(62/160)], CC基因频率及C等位基因频率低于非DVT组[5.00%(1/20)比47.50%(38/80)和20.00%(8/40)比61.25%(98/160)], 差异有统计学意义(P<0.05), 两组CT基因频率比较差异无统计学意义(P>...     

MTHFR和MTRR的SNP多态性与汉族孕妇复发性流产的相关性分析

目的 探究MTHFR和MTRR的SNP多态性与汉族孕妇复发性流产的相关性.方法 选取2012年1月至2015年2月无明确原因复发性流产而至昆山市第四人民医院妇产科就诊的非妊娠妇女190例归为观察组,另外选取同时间段进行体检的健康非妊娠妇女180例为对照组,比较两组妇女MTHFR基因C677T、A1298C和MTRR基因A66G基因位点的单核苷酸多态性(SNP).结果 观察组妇女MTHFR基因C677TT等位基因分布频率为32.11%,对照组为21.94%,观察组显著高于对照组(χ2=9.647,P=0.002).观察组妇女MTHFR基因A1298C等位基因分布频率为34.47%,对照组为30.83%,两组比较无显著性差异(χ2=1.113,P=0.291).观察组妇女MTRR基因A66GG等位基因分布频率为32.37%,对照组为15.28%,观察组显著高于对照组(χ2=29.558,P=0.000).结论 MTHFR基因C677T位点、MTRR基因A66G位点的多态性与复发性流产密切相关.     

冠心病患者亚甲基四氢叶酸还原酶和内皮型一氧化氮合酶基因串联重复序列多态性与同型半胱氨酸水平相关性分析

目的 分析亚甲基四氢叶酸还原酶(MTHFR)基因C677T多态性、内皮型一氧化氮合酶(NOS3)的基因串联重复序列(VNTR)多态性与血浆同型半胱氨酸(Hcy)水平关系,以及2种突变对Hcy的影响。方法 选择冠心病患者153例,同时选取149例对照组。应用体外扩增-酶切长度多态性(PCR-RFLP)技术检测MTHFR基因C677T位点基因多态性、应用凝胶电泳检测NOS3 VNTR基因多态性。结果 Hcy水平在TT基因型中最高,在CC基因型中最低;冠心病(CHD)组的T等位基因频率显著高于对照组; CHD组的4a等位基因频率显著高于对照组。在CHD组中,Hcy水平在4a4a基因型中最高; TT4a4a基因型血浆Hcy最高,CC4b4b基因型血浆Hcy水平最低。结论 MTHFR C677T基因多态性和NOS3 VNTR可影响Hcy水平,其两者联合突变对血浆高Hcy有共同促进作用。     

MTHFR C677T基因多态性与食管癌及食管癌前病变的遗传易感性研究

目的研究亚甲基四氢叶酸还原酶(MTHFR)C677T基因多态性与食管癌发生风险的关系。方法选取中国食管癌高发区173名食管癌新发病例,150名食管癌前病变患者和207名健康人。采用聚合酶链反应-限制性片段长度多态性(PCRRFLP)方法检测MTHFR C677T基因多态性。应用卡方检验分析对照组、食管癌前病变组(轻、中和重度)和食管癌组MTHFR基因型频率分布。结果 MTHFR C677T基因型分布在对照组和食管癌组中无显著性差异。食管癌前病变组MTHFR 677TT基因型和T等位基因频率分布与对照组比较有显著差异(P0.05)。中、重度食管癌前病变组TT基因型和中度组T等位基因频率分布与轻度组比较有显著差异(P0.05)。结论 MTHFR C677T基因多态性可能与食管癌易感性无关,但与食管癌前病变易感性存在相关性,携带MTHFR 677TT基因型和T等位基因的个体发生食管癌前病变的危险性较高。     

亚甲基四氢叶酸还原酶基因多态性与先天神经管缺陷的关系

目的:研究同型半胱氨酸代谢相关酶中亚甲基四氢叶酸还原酶(MTHFR)基因的多态性与先天神经管缺陷发病的相关性。方法:采用病例对照研究的方法,以71例先天神经管缺陷的胎儿及新生患儿(疾病组)与140例无先天神经管缺陷的胎儿及新生儿(对照组)的血白细胞为样本,应用聚合酶链反应-限制性片段长度多态性技术检测两组的MTHFR基因第677位点的多态性,比较两组的基因型和等位基因的分布频率,将疾病组按先天神经管缺陷分布分为单畸形组和多畸形组,分别为23、48例,比较两组的基因型和等位基因的分布频率。结果:MTHFR的677位点CC、CT和TT基因型频率在疾病组中分别为26.76%、43.66%、29.58%,在对照组中分别为43.57%、44.28%、12.14%,两组的分布频率差异有显著性(P<0.05);而在单畸形组中分别为26.09%、43.48%、30.43%,在多畸形组中分别为27.08%、39.58%、33.33%,两组的分布频率无显著差异性(P>0.05)。结论:①MTHFR基因第677位点的多态性与先天神经管缺陷的发病具有一定程度的相关性;②MTHFR基因第677位点中的C/C可能为先天神经管缺陷的保护基因;③此位点的变异与先天神经管缺陷的分布无明显相关性。     

血浆同型半胱氨酸水平及MTHFR基因多态性与阿尔茨海默病的关系

目的 探讨血浆同型半胱氨酸(Hcy)水平及MTHFR基因多态性与阿尔茨海默病(AD)的关系. 方法 选取43例AD患者(AD组),应用高效液相色谱-电化学检测(HPLC-ED)法测定血浆Hcy水平,应用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)检测MTHFR基因多态性,同时测定血浆叶酸、维生素B12水平,并与40例健康老年人(对照组)比较. 结果 AD组血浆Hcy水平为(25.43±5.60)μmol/L,显著高于对照组的(9.81±2.86)μmol/L(P＜0.01),血浆叶酸、维生素B12水平明显低于对照组(P＜0.05);MTHFR基因型有3种,即纯合子(T/T)型、杂合子(T/C)型和纯合子(C/C)型,两组MTHFR基因型和等位基因频率比较差异均无统计学意义(P＞0.05). 结论 高Hcy血症是AD发生和发展的一个重要危险因素.     

MTHFRC677T基因多态性与复发性流产的关系

目的探讨亚甲基四氢叶酸还原酶(methylenetetrahydrofolate reductase,简称MTHFR)C677T基因多态性与复发性流产(recurrent abortion,简称RA)发病的相关性。方法采用聚合酶链反应—限制性片段长度多态性(PCR-RFLP)分析RA组60例和对照组60例MTHFRC677T的基因型。结果RA孕妇及胚胎绒毛组织MTHFR677TT基因型频率和T等位基因频率高于对照组(p<0.05);MTHFR677的3种基因型在流产组和对照组的分布差异有统计学意义(p<0.01),流产组CT TT基因型频率也高于对照组(p<0.05)。结论RA患者和胚胎绒毛组织MTHFR677TT突变与RA有相关性。     

MTHFRC677T基因多态性与复发性流产的关系

目的探讨亚甲基四氢叶酸还原酶（methylenetetrahydrofolate reductase，简称MTHFR）C677T基因多态性与复发性流产（recurrent abortion，简称RA）发病的相关性。方法采用聚合酶链反应-限制性片段长度多态性（PCR-RFLP）分析RA组60例和对照组60例MTHFRC677T的基因型。结果RA孕妇及胚胎绒毛组织MTHFR677TT基因型频率和T等位基因频率高于对照组（p〈0．05）；MTHFR677的3种基因型在流产组和对照组的分布差异有统计学意义（p〈0．01），流产组CT＋TT基因型频率也高于对照组（p〈0．05）。结论RA患者和胚胎绒毛组织MTHFR677TT突变与RA有相关性。     

Methylenetetrahydrofolate reductase polymorphism determines the plasma homocysteine-lowering effect of large-dose folic acid supplementation in patients with cardiovascular disease

OBJECTIVE: The polymorphism of the gene encoding methylenetetrahydrofolate reductase (MTHFR) and folic acid nutritional status play important roles in atherosclerosis. The present study investigated the total homocysteine-lowering effect of folic acid in response to the MTHFR genotype in patients who have cardiovascular disease. METHODS: Twenty-three patients who had cardiovascular disease (ages 44 to 88 y) were supplemented with 5 mg of folic acid/d for 8 wk. Blood samples were collected before and after supplementation for the measurement of folic acid. The presence of the 677C-->T mutation was assessed by polymerase chain reaction followed by restriction enzyme analysis. RESULTS: After the 8 wk of folic acid supplementation, plasma total homocysteine decreased 40% in patients who had the TT genotype, 23% in those who had the CT genotype, 10% in those who had the CC genotype, and 27% in carriers of the T allele. The plasma total homocysteine-lowering effect of folic acid was significant only in patients who had the CT genotype and in carriers of the T allele. CONCLUSIONS: The MTHFR polymorphism may be involved in the total homocysteine-lowering effect of folic acid in patients who have cardiovascular disease.     

MTHFR基因多态性与冠心病关系的Meta分析

目的评价中国人群中亚甲基四氢叶酸还原酶(MTHFR)基因C677T多态性与冠心病的相关性。方法通过文献检索收集MTHFR基因C677T多态性与冠心病关系的全文文献,剔除不符合要求的文献,在全面文献回顾的基础上对各研究OR值进行Meta分析。结果共有16篇符合条件的文献纳入分析,Meta分析结果表明,以野生型CC基因别为参照,携带T等位基因的个体发生冠心病的危险性的0R值为1.45,95%可信区间为(1.12,1.89),P<0.01。结论中国人群中T等位基因携带者易于发生冠心病。     

The effect of 677C-->T and 1298A-->C mutations on plasma homocysteine and 5,10-methylenetetrahydrofolate reductase activity in healthy subjects

We have studied the effect of common mutations (677C-->T and 1298A-->C) of the methylenetetrahydrofolate reductase (MTHFR) gene in sixty-six healthy French subjects, aged 27-47 years. Serum folate, vitamin B12, and plasma total homocysteine were measured as well as the specific activity of MTHFR in lymphocytes. The frequency of subjects homozygous for the 677TT genotype was 18%, and that of those homozygous for the 1298CC genotype was 12.5%. The frequency of individuals heterozygous for both mutations was 23.5%. The 1298A-->C mutation was associated with decreased MTHFR specific activity in subjects with both 677CC and 677CT genotypes. This activity was 60% for the 677CC/1298AC genotype and 52% for the 677CC/1298CC genotype when compared with the MTHFR specific activity of the 677CC/1298AA genotype. Heterozygotes for both mutations (677CT/1298AC genotype) had 36% of the reference specific activity. Although homocysteine levels in 677TT and 1298CC genotype subjects were higher than for other genotypes, no significant differences were observed among different genotypes. This may be due to high serum folate level in our samples, and suggests that folate therapy may be useful to prevent hyperhomocysteinaemia in homozygous mutant subjects.     

胃癌亚甲基四氢叶酸还原酶基因多态性及其与微卫星不稳的关系

目的探讨胃癌亚甲基四氢叶酸还原酶（MTHFR）基因多态性与微卫星不稳的关系。方法采用聚合酶链反应一限制性片段长度多态性技术检测122例胃癌和101名正常对照的MTHFR基因C677T和A1298C多态性；采用PCR为基础的方法检测微卫星不稳定性（MSI）。结果MTHFR C677T多态性可分为677CC、677CT和677TT三种类型。胃癌组3种基因型频率分别为47．5％、39．3％和13．1％；对照组分别为48．5％、42．6％和8．9％，两组相比差异无统计学意义（P〉0．05）。以677CC基因型做为参考，胃贲门癌677CT基因型OR值为0．38，95％CI：0．15～0．98；TT基因型OR值为0．26，95％CI：0．03～2．18；677CT＋TT基因型OR值为0．36，95％CI：0．07～0．98。胃体癌677TT基因型OR值为3．03，95％CI：1．07～8．65。MTHFR A1298C多态性可分为1298AA、1298AC和1298CC3种类型。胃癌组3种基因型频率分别为59．8％、36．1％和4．1％；对照组分别为57．4％，37．6％和5．0％，两组相比差异无统计学意义（P〉0．05）。以1298AA基因型的OR值为1．00，胃窦癌AC基因型的OR值为0．87，95％CI：0．42～1．82，CC基因型的OR值为0．41，95％CI：0．05～3．72。MTHFR 677TT基因型胃癌与微卫星不稳显著相关（P〈0．05），而MTHFR A1298C多态性与微卫星不稳无关（P〉0．05）。结论重庆地区人群中MTHFR C677T多态性是胃贲门癌的保护因素，是胃体癌的危险因素；MTHFR A1298C多态性可能是胃窦癌的保护因素；677TT基因型胃癌的发生可能涉及到MSI途径。     

Contribution of thermolabile methylenetetrahydrofolate reductase variant to total plasma homocysteine levels in healthy men and women. Inter99 (2)

Elevation in plasma total homocysteine (tHcy) is believed to be causally related to cardiovascular disease. Like age and sex, the thermolabile variant of methylenetetrahydrofolate reductase (MTHFR(C677T)) is an important nonmodifiable determinant of tHcy, which may be considered when describing normal ranges of tHcy in the general population. We investigated the simultaneous effect of sex, age, and MTHFR(C677T) genotype on the distribution of tHcy in a cross-sectional study design. THcy concentrations and MTHFR(C677T) genotype were determined in a population-based sample of 2,788 Danish men and women aged 30-60 years participating in the Inter99 Study. The prevalences of MTHFR(C677T) genotypes were 48.8% (CC), 42.4% (CT), and 8.8% (TT). The overall median tHcy was 8.1 micromol/l, and the 2.5-97.5 percentiles were 4.8-17.8 micro mol/l. The estimated proportionally higher level of tHcy in men compared to women was 14.3% (P<0.001). A significant interaction term was found between age and MTHFR(C677T) genotype (P<0.001). The estimated changes in tHcy per 5 years of age were 1.5% in CC individuals (P<0.01), 2.1% in CT individuals (P<0.001), and -4.1% in TT individuals (P<0.01). The T allele was associated with elevated tHcy. However, the proportionally higher level of tHcy in TT individuals compared to CT and CC individuals decreased with increasing age. The MTHFR(C677T) polymorphism explained 6% of the phenotypic variation in tHcy. In conclusion, we found that tHcy is associated with sex, age, and MTHFR genotype. Our results indicate that the effect of age is modified by MTHFR genotype.     

MTHFR基因多态性对药物联合干预H型高血压血浆Hcy动态监测的影响

目的 研究H型高血压患者服用马来酸依那普利叶酸片对血浆同型半胱氨酸（Hcy）水平的影响及亚甲基四氢叶酸还原酶（MTHFR）基因多态性对该疗效监测的预警作用. 方法 依托深圳南山区脑卒中社区综合防治项目,选取150例H型高血压患者和80例对照者,采用聚合酶链反应-限制性片段长度多态性（PCR-RFLP）法检测MTHFR基因多态性,分析不同基因型Hcy的差异.同时循环酶法测定95例H型高血压患者服用马来酸依那普利叶酸片4周前后血浆Hcy水平变化. 结果 H型高血压组中CC、CT、TT不同基因型Hcy水平差异有统计学意义,尤以TT基因型Hcy水平最高（P＜0.01）.95例H型高血压组采用马来酸依那普利叶酸片进行4周干预后,TT基因型Hcy水平下降幅度最大,差异有统计学意义（P＜0.05）. 结论 H型高血压人群中MTHFR基因677C/T纯合突变TT基因型可能是Hcy升高的重要遗传因素.应用马来酸依那普利叶酸片可有效降低高血压患者发生高Hcy血症的风险,其中以MTHFR基因TT型者为最明显.     

MTHFR基因C677T和A1298C多肽与直肠癌的遗传易感性

目的探讨叶酸代谢中的亚甲基四氢叶酸还原酶(MTHFR)基因单核苷酸多肽与直肠癌风险的关系。方法以聚合酶链反应和限制性片段长度多态方法,对56例直肠癌患者和143例正常人对照的MTHFR基因C677T和A1298C基因型进行检测分析其对直肠癌风险的相关性。结果在正常对照组中,MTHFRC677TCC、CT、TT基因型频率分别为62·90%、35·08%和2·12%,而在直肠癌病人中分别为58·93%、26·77%和14·26%。A1298C与A1298C基因型在病例和对照中的分布差异无显著性意义。MTHFRA1298C基因型在病例和对照中的分布差异无显著性意义,1298变异基因型与677变异基因型之间无协同作用。结论MTHFR单核苷酸多肽不是中国人直肠癌的遗传易感性因素。     

Methylenetetrahydrofolate reductase 677C-->T variant modulates folate status response to controlled folate intakes in young women

A common genetic variant in the methylenetetrahydrofolate reductase (MTHFR) gene involving a cytosine to thymidine (C-->T) transition at nucleotide 677 is associated with reduced enzyme activity, altered folate status and potentially higher folate requirements. The objectives of this study were to investigate the effect of the MTHFR 677 T allele on folate status variables in Mexican women (n = 43; 18-45 y) and to assess the adequacy of the 1998 folate U.S. Recommended Dietary Allowance (RDA), 400 micro g/d as dietary folate equivalents (DFE). Subjects (14 CC, 12 CT, 17 TT genotypes) consumed a low folate diet (135 micro g/d DFE) for 7 wk followed by repletion with 400 micro g/d DFE (7 CC, 6 CT, 9 TT) or 800 micro g/d DFE (7 CC, 6 CT, 8 TT) for 7 wk. Throughout repletion with 400 micro g/d DFE, the TT genotype had lower (P 0.05) in their response relative to the CC genotype. Throughout repletion with 800 micro g/d DFE, the CT genotype had lower (P 0.05) in the measured variables between the TT and CC genotypes. Repletion with 400 micro g/d DFE led to normal blood folate and desirable plasma tHcy concentrations, regardless of MTHFR C677T genotype. Collectively, these data demonstrate that the MTHFR C-->T variant modulates folate status response to controlled folate intakes and support the adequacy of the 1998 folate U.S. RDA for all three MTHFR C677T genotypes.