亚甲基四氢叶酸还原酶C677T与A1298C基因多态性在卡培他滨治疗中晚期结直肠癌患者的临床意义

目的 探讨亚甲基四氢叶酸还原酶（MTHFR）C677T与A1298C基因多态性在卡培他滨治疗中晚期结直肠癌（CRC）患者的安全性及有效性,为临床诊治CRC提供理论依据。方法 收集经病理诊断确诊的中晚期结直肠癌患者50例,用实时荧光定量PCR仪进行MTHFR C677T与A1298C基因多态性检测,观察不同基因型之间安全性及有效性的差异。结果 MTHFR C677T的CC、CT、TT基因型频率分别为46%、40%、14%,TT基因型恶心呕吐的发生率及有效率高于CC与CT基因型,差别具有统计学意义（P<0.05）。MTHFR A1298C的AA、AC、CC基因型频率分别为60%、34%、6%,CC基因型腹泻发生率高于AA与AC基因型,差别具有统计学意义（P<0.05）,MTHFR A1298 C中各基因型有效率差异无统计学意义。结论 MTHFR C677T与MTHFR A1298C基因多态性在卡培他滨治疗CRC患者具有较好的临床意义,但MTHFR A1298C与药物治疗有效率无关。     

MTHFR C677T 多态性与消化系统癌症及冠心病易感性的关系

探讨浙江地区汉族人群亚甲基四氢叶酸还原酶（MTHFR）C677T位点多态性与癌症及冠心病易感性的关系。选取确诊的消化系统癌症（包括胃癌、结肠癌、直肠癌及食管癌）患者、冠心病患者以及健康体检者各100例的全血标本,提取血基因组DNA,采用Real-time PCR和测序两种方法检测MTHFR位点的基因多态性。癌症组的MTHFR基因野生型C/C、杂合基因型C/T及纯合变异型T/T的基因型频率分别为34%、46%和20%,冠心病组为32%、53%和15%,健康对照组为34%、54%和12%。与正常对照组相比,消化系统癌症或冠心病患者MTHFR C677T各基因型的分布均无显著性差异（P＞0.05）。在浙江地区人群中,未发现MTHFR基因C677T多态性与消化系统癌症或冠心病的易感性存在显著相关性。     

同型半胱氨酸及其代谢关键酶MTHFR C677T基因多态性与颅内动脉瘤的关系

目的 探讨同型半胱氨酸（Hcy）及其代谢关键酶N5,10-亚甲基四氢叶酸还原酶（MTHFR）C677T基因多态性与颅内动脉瘤的关系.方法 采用荧光偏振免疫法检测76例颅内动脉瘤患者和77例健康成人的血浆Hcy水平,并利用聚合酶链式反应技术检测其MTHFR C677T基因多态性.结果 颅内动脉瘤组血浆Hcy水平（16.14±6.72）μ mol/L高于对照组（11.20±3.20）μmol/L,两组间的差异有显著性（P〈0.05）.两组MTHFR C677T等位基因频率差异无显著性（P〉0.05）;颅内动脉瘤组MTHFR C677T CT基因型频率明显高于正常对照组（P〈0.01）,患颅内动脉瘤的风险是对照组的2.57倍.CC、CT基因型颅内动脉瘤组患者血浆Hcy水平明显高于对照组（P〈0.01）;颅内动脉瘤组患者CT基因型的血浆Hcy浓度较其它基因型高（P〈0.05）.结论 高Hcy血症与颅内动脉瘤病发生有一定关系,MTHFR CT基因型与颅内动脉瘤明显相关.     

MTHFR、MTRR基因多态性与妊娠期高血压病的关系

目的 探讨叶酸(FA)和同型半胱氨酸(Hcy)代谢过程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)基因多态性与妊娠期高血压病(HDCP)的关系。方法 采用PCR限制性内切酶多态性法检测HDCP患者104例(A组)和健康孕妇92例(C组)MTHFR基因C677T位点(MTHFR C677T)和MTRR基因A66G位点(MTRR A66G)基因多态性,采用循环酶法和微粒子化学发光法分别检测两组血清Hcy和FA水平,分析MTHFR C677T和MTRR A66G基因多态性与HDCP易感性的关系,比较A组不同基因分型血清Hcy和FA水平以及母婴结局。结果 A组MTHFR C677T基因TT基因型频率和T位点等位基因频率高于C组(P<0.05)。两组MTRR A66G基因不同基因型和等位基因频率相仿(P>0.05)。MTHFR C677T基因多态性与HDCP易感性有关,CT、TT基因型孕妇发生HDCP风险高(P<0.05)。A组MTHFR C677T基因CC、CT基因型血清Hcy水平降低,而血清FA水平升高(P<0.05)。A组MTHFR C...     

MTHFR C677T与缺血(出血)性脑卒中风险相关性评估

目的 本研究旨在探讨在中国安徽人群中MTHFR C677T基因多态性和脑卒中发生风险的相关性。方法 这项病例对照研究收集了561例样本,其中259例脑梗塞者、96例脑出血者和206例健康对照。利用PCR-RFLP技术来检测MTHFR C677T(Ala222Val)基因多态性位点。结果 多元logistic回归分析结果显示:MTHFR C677T多态性位点与卒中各亚型包括大血管动脉粥样硬化性梗死、心源性梗死、小血管闭塞性梗死、其他确切原因梗死和出血性卒中五种亚型发生风险均没有显著相关性,但是携带MTHFR 677TT基因型的梗塞性卒中患者和DBP显著相关[(5.6±2.3)mmHg,P=0.015],即677TT基因型患者DBP水平要显著高于其他基因型携带者。结论 尽管MTHFR C677T基因多态性不影响缺血性卒中、出血性卒中发生风险,但可能影响卒中患者的血压水平。     

长治市女性亚甲基四氢叶酸还原酶基因多态性分析

目的了解亚甲基四氢叶酸还原酶(MTHFR)C677T基因多态性在长治女性人群的分布情况。方法采用实时荧光定量聚合酶链反应(q PCR)方法,对829例女性的MTHFR C677T基因多态性进行检测。结果本地区女性人群MTHFR 677位点CC、CT、TT基因型频率分别为17.61%,45.11%,37.27%;C和T等位基因频率为40.17%和59.83%。本地区女性MTHFR的基因型和等位基因频率与郑州、廊坊地区比较差异无统计学意义(P>0.05),与珠海、云南、温州、苏州、西安、长春、齐齐哈尔女性比较差异有统计学意义(P<0.05)。结论本研究中MTHFR C677T基因多态性在女性人群中的分布符合Hardy-Weinberg平衡,为本地女性优生优育及叶酸代谢相关疾病提供流行病学资料。     

甲氨蝶呤引起急性肝损伤1例

收集因服用甲氨蝶呤引起急性肝损伤的患者外周静脉血,利用DNA抽提和焦磷酸测序法检测MTHFR的C677T基因型,经检测,患者的MTHFR的C677T基因型为CT型。探讨甲氨蝶呤引起急性肝损伤与亚甲基四氢叶酸还原酶(MTHFR)的C677T基因型是否存在相关性。本例患者甲氨蝶呤引起急性肝损伤可能与MTHFR的C677T基因型存在相关性,建议在用甲氨蝶呤前给予患者进行血液基因检测,利于保障患者用药安全。     

老年冠心病患者MTHFR基因多态性研究

目的探讨N5,N10亚甲基四氢叶酸还原酶（MTHFR）基因多态性与老年冠心病的关系。方法应用聚合酶链反应-限制性片段长度多态性（PCR-RFLP）检测114例冠心病患者及31例对照组MTHFR基因多态性。结果冠心病组与对照组MTHFR基因C677T位点各基因型频率、T等位基因频率、T/T纯合子频率差异无显著性差异。结论MTHFR基因多态性与老年冠心病无显著关系,不能被确定为老年冠心病的独立危险因素。     

N5,N10-亚甲基四氢叶酸还原酶基因多态性与青年脑梗死的关系

目的 研究N5,N10 -亚甲基四氢叶酸还原酶(MTHFR)基因多态性与青年脑梗死的关系.方法 将67例青年脑梗死患者作为病例组,同期71例健康体检者作为对照组,用聚合酶链反应-限制性内切酶片段长度多态性分析(PCR-RFLP)的方法来观察MTHFR 677和1298位点基因型.结果 MTHFR 677位点基因型病例组中TT型为20例,占29.8％;CT型32例,占47.8％;CC型15例,占22.4％;T等位基因频率为53.7％.对照组中TT型30例,占42.2％;CT型34例,占47.9％;CC型7例,占9.9％;T等位基因频率为66.2％.对照组中TT型及T等位基因频率明显高于病例组,2组差异有统计学意义(P＜0.05).MTHFR1298位点基因型病例组中AC型29例,占43.3％;AA型38例,占56.7％;C等位基因频率为21.6％.对照组中AC型14例,占19.7％,AA型57例,占80.3％,C等位基因为9.9％,病例组中AC型及C等位基因频率明显高于对照组,2组差异有统计学意义(P＜0.05).结论 本组人群中MTHFR基因677及1298位点多态性与青年脑梗死都有相关性.     

MTHFR基因多态性与脑卒中的关系

目的 探讨同型半胱氨酸代谢过程的关键酶之一-甲烯四氢叶酸还原(MTHFR)基因多态性与脑卒中发病的关系。方法采用PCR技术和限制性内切酶片段长度多态性方法检测患者的MTHFR基因C677T位碱基突变。结果MTHFR基因C677T突变型等位基因(T)频率在病例组和对照组中有显著性差异(x2=5.01,P<0.05),TT、CT两种基因型频率无显著性差异,而CC基因型频率在两组有显著性差异。基因型频率的相对风险分析,CT基因型比CC基因型患脑卒中风险高2.09倍,TT基因型比CC基因型患脑卒中风险高3.00倍。结论 MTHFR基因突变型等位基因与脑卒中有一定的关联,突变基因型增加了脑卒中的发病风险。     

Linkage disequilibrium between the 677C>T and 1298A>C polymorphisms in human methylenetetrahydrofolate reductase gene and their contributions to risk of colorectal cancer

A common polymorphism in a folate-metabolizing gene, methylenetetrahydrofolate reductase (MTHFR) 677C>T has been associated with reduced risk of colorectal cancer. In this study, we investigated whether a second common polymorphism of the gene, MTHFR 1298A>C, is an independent risk factor for colorectal cancer and if it is associated with plasma folate and total homocysteine (tHcy) levels. We also examined whether the 677C>T and 1298A>C polymorphisms are in linkage disequilibrium and whether combined heterozygosity confers additional (or reduced) risk of colorectal cancer. We conducted a nested case-control study of 211 incident colorectal cancer cases and 343 controls in the prospective Physicians' Health Study. The MTHFR 677C>T and 1298A>C polymorphisms were in linkage disequilibrium in this population. Compared to MTHFR 1298AA genotype, multivariate-adjusted relative risk of colorectal cancer was 0.73 (95% CI 0.37-1.43) for the MTHFR 1298CC genotype. The slight reduction in risk was not a result of its linkage disequilibrium with the 677C>T polymorphism. This polymorphism was not significantly correlated with the plasma folate and tHcy levels. The combined heterozygosity did not modify the cancer risk; nor did it change the plasma folate and tHcy significantly. We conclude that the MTHFR 1298A>C polymorphism is a less substantial independent risk factor for colorectal cancer compared to the 677C>T polymorphism.     

Methylenetetrahydrofolate reductase gene polymorphisms and response to fluorouracil-based treatment in advanced colorectal cancer patients

Methylenetetrahydrofolate reductase (MTHFR) controls intracellular CH2FH4 concentrations (required for optimal fluoropyrimidine efficacy) by irreversibly converting CH2FH4 into 5-methyltetrahydrofolate. MTHFR 677C>T and 1298A>C polymorphisms are linked to altered enzyme activity. Thus, mutated MTHFR tumours should, in theory, be more sensitive to 5-fluorouracil (5FU) than wild-type tumours. MTHFR polymorphisms in position 677 and 1298 were analysed in 98 colorectal cancer patients with unresectable liver metastases (57 men, 41 women, mean age 64 years) receiving 5FU-folinic acid. 677C>T and 1298A>C genotypes were determined simultaneously by melting curve analyses on liver metastases. 677C>T genotype distribution was 46.9% wt/wt, 34.7% wt/mut and 18.4% mut/mut; that of 1298A>C was 52.0% wt/wt, 35.7% wt/mut and 12.3% mut/mut. The response rate was not related to 1298A>C genotype but was significantly linked to 677C>T genotype (response rate: 40%, 21% and 56% in wt/wt, wt/mut and mut/mut, respectively; P = 0.040), with an increased response rate in mut/mut tumours relative to wt/wt (odds ratio = 1.88). Thymidylate synthase activity measured in metastases was a significant predictor of 5FU responsiveness and the addition of the 677C>T genotype improved model prediction. MTHFR 1298A>C polymorphism was significantly linked to specific survival, with homozygous mutated patients having the worst prognosis (P = 0.009, relative risk = 2.48 in mut/mut versus wt/wt). MTHFR 1298A>C genotype remained a significant predictor in a multivariate analysis including metastasis characteristics. The results suggest that MTHFR genotypes are relevant and independent factors of patient outcome in 5FU-based treatment of advanced colorectal cancer.     

血液肿瘤患儿MTHFR和ABCB1基因多态性与甲氨蝶呤骨髓抑制的相关性

目的探究血液肿瘤患儿应用大剂量甲氨蝶呤(HD-MTX)化疗后骨髓抑制与MTHFR和ABCB1基因多态性的相关性,为临床个体化用药提供参考依据。方法选取徐州医科大学附属医院2019-2020年收治的94例接受HD-MTX化疗的患儿,收集外周血,用直接测序法测定MTHFR和ABCB1的基因型,统计患儿化疗前后血常规信息。参照世界卫生组织推荐的化疗药物毒副反应分级标准,将骨髓抑制严重程度分为轻度(0～Ⅱ级)和重度(Ⅲ级以上)。结果 94例患儿中,MTHFR C677T位点TT型的构成比为26.60%,CT为44.68%,CC为28.72%,ABCB1 C3435T位点的CC、CT和TT基因型的构成比分别为45.74%,36.17%和18.09%。共有45例(47.87%)患儿发生了Ⅲ级以上甲氨蝶呤相关的骨髓抑制。MTHFR C677T位点为野生型CC的患儿发生Ⅲ级以上骨髓抑制比率低于杂合型CT携带者,差异具有统计学意义(P<0.05)。ABCB1 3435位点为CC的患儿率发生Ⅲ级以上骨髓抑制的比率显著低于TT型携带者和至少携带1个等位基因T(CT+TT基因型)的患者(P<0.0...     

MTHFR基因多态性与下肢DVT的相关性研究

目的探讨N5,N10-亚甲基四氢叶酸还原酶(Methylenetetrahydrofolatereductase,MTHFR)基因多态性与我国东北地区人群下肢深静脉血栓形成(Deepvenousthrombosis,DVT)的关系。方法采用PCR-RFLP检测73例DVT患者和109名健康对照者MTHFRC677T、A1298C突变,计算患者组与对照组的基因型频率、等位基因频率以及突变与DVT的相关性。结果患者组677TT、677CT基因型频率和T等位基因频率分别为38.4%、49.3%和63%,明显高于对照组(分别为15.6%、46.8%和39%。χ2=19.393,P<0.01;χ2=20.200,P<0.01)。677TT和677CT基因型的个体比677CC基因型的个体发生DVT的相对危险分别约高7或3倍(ORTT=7.503,95%可信区间为2.931～19.207;ORTC=3.215,95%CI为1.391～7.434)。患者组与对照组MTHFR1298各基因型和等位基因分布无显著性差异(χ2=3.533,P>0.05;χ2=0.100,P>0.05),但1298CC677CC基因型的个体比1298AA、677CC基因型的个体发生DVT的相对危险约高16倍(OR=16.500,95%CI为1.353～201.290)。结论MTHFR基因C677T和A1298C突变可能为我国东北地区人群下肢DVT的危险因素。     

甲氨蝶呤血药浓度和基因检测在治疗低危妊娠滋养细胞肿瘤中的价值研究

目的:为甲氨蝶呤对低危妊娠滋养细胞肿瘤(low-risk gestational trophoblastic neoplasia,LRGTN)的个体化治疗提供研究基础和依据.方法:观察甲氨蝶呤治疗后出现明显不良反应的3例LRGTN患者的临床症状,检测甲氨蝶呤的血药浓度、亚甲基四氢叶酸还原酶(methylenetetra...     

MTHFR基因多态性与冠心病的关系

目的研究天津地区人群N5,N10-亚甲基四氢叶酸还原酶(MTHFR)基因C 677 T多态性与冠心病的关系.方法应用聚合酶链反应(PCR)技术和限制性酶切片段长度多态性(RFLP)分析技术检测50例冠心病患者(冠心病组)和50例正常人(对照组)MTHFR基因C 677 T多态性,应用高效液相色谱法测定血浆同型半胱氨酸(Hcy)水平,采用125Ⅰ标记放免法测定血清叶酸浓度.结果(1)冠心病组与对照组MTHFR基因频率分布不同(P＜0 05),对照组CC型、TC型、TT型基因频率分别为52.0%,28.0%,20.0%;冠心病组分别为26.0%,44.0%,30.0%.冠心病组T等位基因频率为52.0%,C等位基因频率为48.0%,与对照组比较有显著性差异(P＜0.05).(2)两组的TT基因型者血浆Hcy浓度均明显高于CC和TC基因型者(P＜0.05),而后两者间无显著性差异(P＞0.05).(3)冠心病组Hcy浓度高于对照组(P＜0.05).两组叶酸水平无显著性差异(P＞0.05),血浆Hcy浓度与叶酸水平均呈显著负相关(r分别为-0.617和-0.588,P＜0.05).结论MTHFR基因C 677 T点突变与冠心病发病密切相关,MTHFR基因纯合突变是引起高Hcy血症的一个重要的遗传因素.     

Correlation Between C677T MTHFR Gene Polymorphism, Plasma Homocysteine Levels and the Incidence of CAD

The lesions of coronary atherosclerosis represent the result of a complex, multicellular, inflammatoryhealing response in the coronary arterial wall. In vivo and in vitro cellular and molecular studies have suggested a role for tissue homocysteine in endothelial cell injury and adverse extra-cellular matrix remodeling. Gene polymorphisms in relation with numerous risk factors might increase the incidence of coronary artery disease (CAD). In this review we have focused on the correlations between plasma homocysteine levels, the incidence of cardiovascular disease and the cytosine-to-thymidine substitution at nucleotide 677 (C677T) of the 5, 10-methylenetetrahydrofolate reductase (MTHFR) gene, coding for a key enzyme in methionine-homocysteine metabolism. The role of the C677T MTHFR gene polymorphism in the causation of CAD is controversial. We reviewed 12 recent case-control studies comprising 5370 genotyped patients with CAD and 4961 genotyped participants without CAD. There was no significant difference between those with and without CAD in the frequency of the C677T polymorphism (34.9 vs 33.6%). The frequency of homozygous C677T polymorphism in these groups was 10.9 versus 12.8%, respectively, although there were some ethnic differences in the C677T MTHFR polymorphism. In the analysis of the 12 studies, the odds ratio of CAD associated with the TT genotype (homozygous C677T polymorphism) was 1.18. Only slightly higher plasma homocysteine levels were observed in participants with the val/val (TT) genotype (14.4 ± 2.9 μ.mol/L in TT genotype vs 11.1 ± 1.9 and 11.9 ± 2 μ.mol/L in CC and CT genotype, respectively). In addition, the relation between homocysteine increase after methionine loading and MTHFR genotypes is also controversial. However, hyperhomocysteinemia because of the C677T MTHFR allele may be corrected with oral folic acid therapy. Further investigations on the relationships between MTHFR genotypes and the incidence of CAD should be based on larger samples, paying attention to the differences between various ethnic populations. Individual therapeutic strategies based on single nucleotide polymorphism may become increasingly important for preventive treatment against polygenic CAD.     

GeXP多重分析技术对四氢叶酸还原酶基因多态性与先天性心脏病相关性的研究

目的：利用GeXP多重分析技术,探讨四氢叶酸还原酶基因（ MTHFR）多态性与先天性心脏病相关性。方法收集2013年2月至2014年12月河北省儿童医院心脏外科手术的261例先心病患儿及49例健康对照儿童外周血,提取全血DNA,使用GeXP多重测序平台的多重分析技术对其MTHFR基因上的两个易感位点rs1801131和rs1801133进行基因分型,采用SPSS 16倐．0软件的χ2检验,分析先心病与MTHFR基因多态性的相关性。结果 GeXP多重测序平台可同时测量2个SNP的四种基因型,先心病组与对照组MTHFR677C／T等位基因和基因型频率差异无统计学意义（χ2＝0．853, P ＝0．356;χ2＝0．898, P ＝0．343）。结论 GeXP多重分析平台是筛查先心病易感基因特异性良好、操作简便的多重分析技术,本研究入选的先心病患儿与健康对照MTHFR等位基因或其基因型分布无显著性差异,为后期大样本量探寻先心病发病易感基因起到启示作用和奠定了方法学基础。     

叶酸代谢酶MTHFR、MTRR基因多态性与原因不明复发性流产的关系

目的 探讨叶酸代谢相关酶亚甲基四氢叶酸还原酶（MTHFR）、甲硫氨酸合酶还原酶（MTRR）基因多态性与原因不明复发性流产（URSA）之间的关系。 方法 采用病例对照的研究方法, 选取天津医科大学总医院和天津市妇女儿童保健中心 2013 年 1 月 1 日—2015 年 3 月 1 日因 URSA 就诊的非妊娠妇女 244 例（URSA 组）和健康非妊娠妇女 116 例（ 对照组）。 获取口腔黏膜上皮细胞, 使用荧光定量 PCR 检测 MTHFR 基因 C677T、A1298C 位点和 MTRR 基因 A66G 位点的单核苷酸多态性（SNP）, 同时测定 MTHFR 酶活性及红细胞叶酸、血浆叶酸、血浆同型半胱氨酸水平, 分析叶酸代谢相关酶 MTHFR、MTRR 基因多态性与 URSA 之间的关系。 结果 URSA 组 MTHFR C677T 位点 TT 基因型频率高于对照组, CT 基因型频率低于对照组（P＜ 0.05）。 2 组间 MTHFR A1298C、MTRR A66G 基因型频率差异无统计学意义。 URSA 组 MTHFR 酶活性、红细胞叶酸、血浆叶酸水平低于对照组, 同型半胱氨酸水平高于对照组（P＜ 0.05）; URSA 组中＜ 35 岁、≥35 岁患者血浆叶酸、红细胞叶酸、同型半胱氨酸水平差异无统计学意义。结论 MTHFR C677T 基因多态性与 URSA 有一定关系。