急性淋巴细胞白血病患儿亚甲基四氢叶酸还原酶基因多态性与甲氨蝶呤动态血药浓度相关性的研究

目的本研究旨在探讨亚甲基四氢叶酸还原酶(MTHFR)C677T、A1298C基因多态性对急性淋巴细胞白血病(ALL)患儿使用大剂量甲氨蝶呤(HD-MTX)化疗期间的MTX动态血药浓度的相关关系。方法 35例ALL患儿外周血,提取基因DNA,应用PCR-RFLP方法检测MTHFR C677T、A1298C基因型;应用荧光偏振免疫分析法(FPIA)24h、48h、72h监测患儿外周血中甲氨蝶呤动态血药浓度。结果 MTHFR C677T各基因型间24 h MTX浓度有差异(P0.05),携带CT型者明显高于携带CC型和TT型者;MTHFR C677T各基因型48 h、72 h的MTX浓度未见差异。MTHFR A1298C各基因型24 h、48 h7、2 h的MTX浓度未见差异(P0.05)。结论 MTHFR C677T基因多态性影响ALL患儿HD-MTX化疗期间MTX血药浓度,提示在HD-MTX治疗时可根据检测MTHFR C677T基因型进行个体化治疗。     

MTHRF基因C677T多态性与ALL患儿MTX血药浓度和毒副反应的相关性

【目的】探讨亚甲基四氢叶酸还原酶（MTHFR）C677T基因多态性对急性淋巴细胞白血病（ALL）儿童甲氨蝶呤（MTX）血药浓度和毒副反应的影响。【方法】筛选50例采用大剂量MTX治疗的ALL患儿,采用多聚酶链反应一限制性内切酶片段多态性分析法（PCR-RFLP）检测MTHFRC677T多态性,应用荧光偏振免疫分析法（FPIA）24h、48h、72h监测患儿外周血中甲氨蝶呤动态血药浓度,记录相关毒副反应。【结果】24h时、48hMTX血药浓度均以突变型纯舍子（TT）最高（均P〈0．05）,突变型杂合子（CT）次元;MTHFRC677T基因型与肝损害、消化道反应和骨髓抑制相关,携带T突变基因患儿（CT＋TT组）发生肝损害的风险是野生型纯合子（CC）的5．12倍（95％CI：1．372～19．077）,发生3～4级消化道反应的风险是CC型的4．41倍（95％CI：1．066～18．266）,3～4级骨髓抑制发生率依次为TT型、CT型和CC型（均P〈0．05）。【结论】MTHFRC677T基因多态性影响ALL患儿大剂量MTX化疗期间MTX血药浓度,与肝损害、消化道反应和骨髓抑制等毒副反应相关。     

亚甲基四氢叶酸还原酶基因多态性与大剂量甲氨蝶呤不良反应的相关性研究

目的探讨亚甲基四氢叶酸还原酶(MTHFR) C677 T、A1298C基因多态性与急性淋巴细胞白血病(ALL)患儿使用大剂量甲氨蝶呤(HD-MTX)后不良反应的相关性。方法纳入70例经HD-MTX治疗的ALL患儿,检测患儿MTHFR C677 T、A1298C基因多态性和MTX血药浓度,收集各项生理生化指标和HD-MTX化疗后不良反应,分析基因多态性与血药浓度及不良反应发生的相关性。结果 C677 T各基因型间胃肠道反应的发生呈显著性差异(P=0. 003),C677 T野生型(CC) vs突变型(CT+TT)胃肠道反应呈显著性差异(P=0. 001),Logistic回归分析显示患儿72小时血药浓度水平、C677 T位点多态性,体质指数(BMI),免疫分型及体重可能是导致患儿不良反应(ADR)发生的影响因素(P 0. 05)。结论检测MTHFRC677T基因型可以有效指导临床HD-MTX个体化给药,为减少不良反应的发生提供参考指标。     

消化道肿瘤患者MTHFR 基因多态性与5- 氟尿嘧啶化疗不良反应的相关性研究

目的　在消化道肿瘤患者中,探讨MTHFR 1298A>C 和MTHFR 677C>T 基因多态性与5- 氟尿嘧啶（5-FU） 化疗出现不良反应的关系。方法　2016 年2~6 月,入组复旦大学附属中山医院肿瘤内科收治的123 例消化道肿瘤患 者。提取外周血中的基因组DNA,通过Sanger 测序检测MTHFR 1298A>C 和MTHFR 677C>T 的基因型。随访其中 98 例含5-FU 治疗方案的患者,分析了不同基因型的患者发生毒副反应的类型及严重程度的区别。结果　123 例消化道 肿瘤患者中,MTHFR 1298A>C 野生型 76 例（61.79%）,杂合型AC 40 例（32.52%）,纯合型CC 7 例（5.69%）。 MTHFR677C>T 野生型CC 50 例（40.65%）, 杂合型CT 61 例（49.59%）, 纯合型TT 12 例（9.76%）。98 例化疗 方案中含5-FU 的患者中,MTHFR 677C>T 突变型（CT 和TT）显著增加化疗后发生不良反应的风险（χ2=4.188, P<0.05）;MTHFR 1298A>C 突变型（AC 和AA）、性别、年龄、治疗方案与使用5-FU 产生的相关毒副作用无显著关 联性。结论　在接受5-FU 治疗的消化道肿瘤患者中,MTHFR 677C>T 多态性显著增加化疗相关毒副反应的发生风险, 该基因可能成为预测氟尿嘧啶类化疗药物发生临床不良事件的风险因素,能够为临床选择合适的治疗方案提供更多的信 息。     

河南汉族人群MTHFR基因多态性与肺癌的关系

目的 探讨河南地区汉族人群5,10-亚甲基四氢叶酸还原酶（methylenetetrahydrofolate reductase,MTHFR）氨基酸突变位点C677T和A1298C基因多态性分布与肺癌发生的关系。方法 202例肺癌患者（肺癌组）和202例体检健康者（对照组）,2组采用限制性片段长度多态性酶切技术检测MTHFR基因型,分析MTHFR基因C677T和A1298C位点基因频率分布特点。结果 肺癌组MTHFR基因C677T位点CC、CT、TT基因亚型分布频率分别为26.7%、50.5%、22.8%,对照组分别为34.2%、55.4%、10.4%,CC、CT亚型与对照组比较差异无统计学意义（P〉0.05）,TT基因亚型与对照组比较差异有统计学意义（P〈0.05）;携带TT基因型患肺癌的风险比值比为2.542,95%CI为1.453~4.444;肺癌组MTHFR基因A1298C位点AA、AC、CC基因亚型分布频率分别为27.2%、52.5%、20.3%,对照组分别为32.2%、50.5%、17.3%,2组比较差异均无统计学意义（P〉0.05）。结论 MTHFR基因C677T基因TT亚型与肺癌的发病明显相关,未发现A1298C基因多态性与肺癌的发生有相关性。     

陕西省延安地区育龄女性MTHFR基因多态性和国内多地区相关报道比较分析

目的分析陕西省延安地区育龄女性叶酸代谢关键酶亚甲基四氢叶酸还原酶(MTHFR)的基因多态性及地区遗传分布特征。方法以延安市第二医疗集团1 508例育龄女性为研究对象,用荧光定量PCR法检测其MTHFR C677T,A1298C基因位点多态性,并和国内多地区相关报道比较分析。结果该地区三种表现型正常型、较弱型和弱型分别占22.5%,50.7%和26.8%。MTHFR C677T位点CC,CT和TT基因频率分别为24.7%,48.6%和26.7%;MTHFRA1298C位点AA,AC和CC基因频率分别为71.0%,26.7%和2.3%,与已报道的南方城市湘潭、武汉、南宁等地区相比,差异均有统计学意义(P0.05)。MTHFR C677T和A1298C等位基因分布情况与其基因型分布情况类似。结论该地区育龄女性MTHFR基因以基因型(MTHFR C677T/A1298C)CT/AA型为主,MTHFR C677TTT纯合突变型呈现北高南低的趋势,其T等位基因频率也呈现随纬度的递减而降低的走向。     

血清同型半胱氨酸及亚甲基四氢叶酸还原酶与先兆流产相关性研究

目的探讨血清同型半胱氨酸(Hcy)水平及亚甲基四氢叶酸还原酶基因(MTHFR)C677T、A1298C位点多态性与先兆流产的关系。方法以93例先兆流产患者为病例组,99例健康孕妇为对照组,采用荧光定量PCR技术检测MTHFR基因C677T和A1298C位点多态性,同时应用酶循环法测定血清Hcy水平。比较病例组和对照组间基因型分布频率和血清Hcy水平差异。结果病例组血清Hcy水平明显高于对照组;高Hcy是先兆流产的危险因素(OR=2.056,P=0.016);MTHFR C677TT基因型携带者血清Hcy水平明显高于其他基因型;A1298CC基因型携带者血清Hcy水平明显高于AA野合型;病例组A1298CC纯合基因频率明显高于对照组;差异均有统计学意义(P0.05)。结论 Hcy升高是导致先兆流产的重要危险因素;MTHFR A1298CC纯合突变可致血清Hcy水平升高与先兆流产的发生有一定的相关性。     

育龄女性MTHFR、MTRR基因多态性分布以及与血清叶酸和同型半胱氨酸水平的相关性研究

目的探讨叶酸代谢关键酶基因5,10-亚甲基四氢叶酸还原酶(MTHFR)C677T、A1298C和甲硫氨酸合成酶还原酶(MTRR)A66G多态性在育龄女性中的分布特征,并分析不同遗传特征对外周血叶酸和同型半胱氨酸(Hcy)水平的影响。方法选取2018年3月至2020年1月在上海计生所医院妇科就诊的汉族育龄女性2 651例,根据知情同意原则,采集口腔黏膜上皮脱落细胞,抽提基因组DNA,使用荧光定量PCR方法检测MTHFR C677T、A1298C和MTRR A66G基因多态性,采用化学发光法检测外周血叶酸水平,循环酶法检测血清Hcy水平。结果 (1)MTHFR C677TCC、CT、TT的基因型频率分别为33.2%、47.9%、18.9%,C、T等位基因频率分别为57.1%、42.9%;MTHFR A1298C AA、AC、CC的基因型频率分别为66.6%、30.5%、2.9%,A、C等位基因频率分别为81.8%、18.2%;MTRR A66G AA、AG、GG的基因型频率分别为56.4%、36.9%、6.8%,A、G等位基因频率分别为74.8%、25.2%。(2)MTHFR C677T和A1298C两位点连锁有7种组合,频率最高的是CT/AA(31.9%),没有CT/CC和TT/CC组合。两位点间存在完全连锁不平衡(D′=0.984,R2=0.161)。(3)MTHFR C677T不同基因型的叶酸和Hcy水平差异有统计学意义(P<0.05)。TT基因型的叶酸水平低于CC基因型,TT基因型的Hcy水平高于CC基因型。经单因素Logistic回归分析发现,MTHFR C677T TT基因型发生高Hcy血症的危险性是CC基因型的9.97倍(95%CI:3.81~26.05)。MTHFR A1298C和MTRR A66G不同基因型与血清叶酸及Hcy水平差异无统计学意义(P>0.05)。(4)经单因素回归分析,Hcy水平与叶酸水平呈负相关(R2=0.061,P<0.05),叶酸水平可解释Hcy水平个体差异的6.1%。结论获取了上海市汉族育龄女性MTHFR和MTRR基因多态性的群体遗传学特征,血清Hcy水平与MTHFR C677T基因多态性以及血清叶酸水平有关。筛查MTHFR和MTRR基因多态性并监测Hcy水平对围生期保健有重要的指导意义。     

叶酸代谢相关酶基因多态性与不良孕产的关系研究

目的分析探讨叶酸代谢相关酶基因多态性与不良孕产间的关系。方法选择2018年1月～2018年8月本院接收的不良孕产妇56例为研究组,另选同一时期正常生育产妇56例为对照组,两组均采用PCR法进行基因多态性检测,对比两组的基因型分布特点,并分析与不良孕产之间的关联性。结果研究组的MTHFR基因A1298C位点CC突变纯合型、C677T位点TT突变纯合型与MTRR基因A66G位点GG突变纯合型的基因频率均较对照组更高(P0.05);而研究组的MTHFR基因A1298C位点AA野生纯合型、C677T位点CC野生纯合型及MTRR基因A66G位点AA野生纯合型基因频率则较对照组更低(P0.05)。结论不良孕产与叶酸代谢相关酶基因多态性之间关系密切。     

亚甲基四氢叶酸还原酶基因多态性与乳腺癌新辅助化疗敏感性关系的研究探讨

目的研究叶酸代谢的关键酶亚甲基四氢叶酸还原酶（MTHFR）基因C677T、A1298C多态与乳腺癌患者对新辅助化疗敏感性的关系。方法收集经病理学或细胞学确诊的乳腺癌患者61例,均给予新辅助化疗。接受环磷酰胺、表阿霉素、5-氟尿嘧啶联合化疗方案（CAF）化疗34例,表阿霉素、紫杉醇联合化疗方案（AT方案）化疗27例。所有病例化疗前抽静脉血,提取白细胞DNA,用聚合酶链反应限制性片段长度多态性（PCR-RFLP）技术检测MTHFR基因型。化疗后均测量肿块大小进行疗效评价,手术均行病理检查,观察化疗反应分级情况。结果 61例乳腺癌患者中,使用CAF方案和AT方案的临床有效率分别为61.5%、75.0%,差异无统计学意义;Ⅰ~Ⅲ级化疗反应率分别为55.9%、74.1%,差异无统计学意义。携带MTHFR C677T T/T基因型、C/T基因型、C/C基因型的乳腺癌患者化疗的临床有效率分别为83.3%、72.4%、42.9%,Ⅰ~Ⅲ级化疗反应率分别为83.3%、65.5%、35.7%。携带T/T基因型乳腺癌患者的临床有效率和Ⅰ~Ⅲ级化疗反应率均显著高于携带C/C基因型的患者,而与携带C/T基因型患者相比差异无统计学意义。携带MTHFR A1298C A/A基因型、A/C基因型、C/C基因型的乳腺癌患者化疗的临床有效率分别为70.5%、64.7%、0.0%,Ⅰ~Ⅲ级化疗反应率分别为70.5%、47.1%、0.0%。携带MTHFR A1298C A/A基因型患者的临床有效率和Ⅰ~Ⅲ级化疗反应率与A/C及C/C基因型患者之间差异均无统计学意义。结论 MTHFR C677T基因多态性的作用与乳腺癌新辅助化疗敏感性之间存在着一定的相关性,对预测乳腺癌新辅助化疗的疗效具有良好的临床应用前景。     

C677T and A1298C polymorphisms of the methylenetetrahydrofolate reductase gene: incidence and effect of combined genotypes on plasma fasting and post-methionine load homocysteine in vascular disease

BACKGROUND: Moderately increased plasma concentrations of total homocysteine (tHcy) have been shown to be an important risk factor for vascular diseases. Two common polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) gene, the thermolabile C677T and a more recently reported A1298C polymorphism, may contribute to hyperhomocysteinemia. METHODS: Using PCR and restriction fragment length polymorphism analysis, we studied the prevalence of the C677T and A1298C MTHFR genotypes and the combined effect of these polymorphisms on plasma tHcy concentrations, as measured by HPLC with fluorometric detection, both fasting and post-methionine load (PML), in 1238 individuals. RESULTS: The prevalences of the C677T and A1298C genotypes did not differ significantly in 772 individuals with documented coronary artery disease (CAD), 137 individuals with deep-vein thrombosis (DVT), and 329 individuals without documented vascular disease. Individuals homozygous for the 677T allele had significantly increased fasting tHcy, particularly in the presence of low folate, compared with individuals homozygous for the wild-type allele. Neither the 1298AC nor the 1298CC genotype was associated with significantly increased fasting or PML tHcy concentrations irrespective of serum folate. Of the nine combined MTHFR genotypes, six were present in >10% of the population. Of these, the difference in mean fasting tHcy reached statistical significance (P<0.005) only in individuals with the 677TT/1298AA genotype compared with individuals with the wild-type 677CC/1298AA genotype. Differences in mean fasting tHcy did not reach statistical significance in individuals heterozygous for both MTHFR variants. We detected two 677CT/1298CC and three 677TT/1298AC individuals; only one, an 677TT/1298AC individual, had increased tHcy (both fasting and PML). No individuals had the 677TT/1298CC genotype. CONCLUSIONS: The prevalences of the C677T and A1298C polymorphisms did not differ among individuals with CAD, DVT, or those without documented vascular disease. In contrast to the C677T polymorphism, the A1298C polymorphism is not associated with increased fasting tHcy. Although the two polymorphisms usually exist in trans configuration, crossover may occur rarely to form recombinant chromosomes.     

潍坊市汉族女性叶酸代谢关键酶基因多态性分布研究

目的:针对潍坊市汉族女性开展分子流行病学调查,研究叶酸代谢关键酶MTHFR和MTRR的基因多态性分布。方法:以孕期保健的670例汉族健康女性为研究对象,采集口腔黏膜上皮脱落细胞,抽提基因组DNA,使用荧光定量PCR方法检测MTHFR C677T、A1298C和MTRR A66G基因多态性,进行统计分析。结果:1)入组对象的基因多态性分布符合遗传平衡。2)汉族女性MTHFR 677CC、CT、TT的基因型频率分别为13.73%、47.91%、38.36%,C、T等位基因频率分别为37.7%、62.3%;MTHFR 1298AA、AC、CC的基因型频率分别为75.52%、23.28%、1.19%,A、C等位基因频率分别为87.2%、12.8%;MTRR 66AA、AG、GG的基因型频率分别为54.63%、40.44%、4.93%,A、G等位基因频率分别为74.9%、25.1%。3)汉族女性MTHFR C677T和A1298C两位点连锁有7种组合,频率最高的是TT/AA(38.21%),没有CT/CC和TT/CC组合。两位点间存在完全连锁不平衡(D'=0.987,r2=0.237)。结论:获取潍坊市汉族女性MTHFR和MTRR基因多态性的群体遗传学特征。     

Association between 5,10-methylenetetrahydrofolate reductase C677T and A1298C polymorphisms and conotruncal heart defects.

Reports related some polymorphisms of the 5,10-methylenetetrahydrofolate reductase (MTHFR) to folate-dependent neural tube defects. In view of the common origin of the cells involved both in neural tube closure and heart septation, we analyzed the MTHFR C677T and A1298C polymorphisms in mothers of children with conotruncal heart defect (CD) and in their offspring to evaluate the association between the MTHFR genotype and the risk of CD. We genotyped 103 Italian mothers with CD offspring, 200 control mothers, 103 affected children and their fathers by restriction fragment length polymorphism analysis. No increased risk was observed for the prevalence of the 677TT genotype by itself in affected children and in their mothers. The combined maternal 677TT/1298AA and 677CC/1298CC genotypes have odds ratio of 1.73 and 1.85, respectively. The prevalence of 1298CC genotype in the affected children gives odds ratio of 1.90, that becomes 2.31 for the 677CC/1298CC genotype. However, none of the odds ratios was statistically significant. We observed a higher frequency of the 677T allele in Italy than in other European countries. No association has been demonstrated between the 677TT MTHFR genotype and CD.     

Methylenetetrahydrofolate reductase gene polymorphisms in Burkina Faso: impact on plasma fasting homocysteine and after methionine loading test

In Burkina Faso the levels of plasma homocysteine (Hcy) are lower and the methionine loading tests suggest a more effective Hcy metabolism. The polymorphisms of methylenetetrahydrofolate reductase (MTHFR) showed a relevant difference in the allele frequencies of T MTHFR-677 in young and in old subjects, while the allele frequency of C MTHFR-1298 was comparable in young and old subjects. The aim of this paper was to study the impact of the MTHFR polymorphisms on plasma fasting Hcy and after methionine loading in Burkina Faso. The young subjects with CC MTHFR-677 genotype had levels of Hcy significantly lower than CT and TT subjects. The level of Hcy in subjects who had AA, AC and CC MTHFR-1298 genotypes were comparable. The levels of Hcy after the methionine loading test were significantly higher in CT and TT MTHFR-677 genotype. These results suggest that the genetic situation in Burkina Faso is different from that of other Western countries and this guarantees the maintenance of lower plasma levels of Hcy in young and old Africans. The elevated levels of plasma Hcy in old subjects compared to young subjects, against the low prevalence of the T allele in elderly subjects, is discussed.     

中国人群MTHFR基因C677T多态性与青中年缺血性脑卒中相关性的Meta分析

目的系统评价中国人群中N5,N10-亚甲四氢叶酸还原酶(MTHFR)基因677位点单核苷酸多态性(C677T)与青中年缺血性脑卒中易感性的相关性。方法计算机检索PubMed、EMbase、h e Cochrane Library(2013年第11期)、CBM、CNKI、VIP及WanFang Data,收集相关中国人群MTHFR基因C677T多态性与青中年缺血性脑卒中关系的病例-对照研究,检索时限均为从各数据库建库至2013年11月。由2位评价者按照纳入与排除标准独立筛选文献、提取资料并评价纳入研究的方法学质量后,采用RevMan 5.2进行Meta分析,并采用Stata 12.0进行敏感性分析和发表偏倚评估。结果共纳入10个病例-对照研究,合计病例787例,对照766例。Meta分析结果显示:在青中年组(年龄<60岁)中,携带T等位基因的人群相对于C等位基因的人群,缺血性脑卒中易感性增加[OR=1.42,95%CI(1.07,1.89),P=0.02];基因型为TT的人群缺血性脑卒中发病风险高于基因型为CC者[OR=2.11,95%CI(1.58,2.81),P<0.000?01];显性模型中TT+TC基因型的人群发病风险高于CC基因型的人群[OR=1.97,95%CI(1.55,2.51),P<0.000?01];隐形模型中TT基因型者发病风险同样高于TC+CC基因型者[OR=1.42,95%CI(1.13,1.77),P=0.003]。而在青年组(年龄<45岁),显性遗传模型的TT+TC基因型者相对于CC基因型者显示出更高的发病风险[OR=1.66,95%CI(1.19,2.32),P=0.003]。结论 MTHFR基因C677T多态性与中国人群青中年缺血性脑卒中的发病具有显著相关性,677T的存在增加发病风险。     

Prevalence of methylenetetrahydrofolate reductase mutations in patients with venous thrombosis.

BACKGROUND: The objectives of this study are to examine the prevalence of combined methylenetetrahydrofolate reductase (MTHFR) 677C-->T and 1298A-->C mutations in patients with venous thrombosis (VT) and healthy volunteers and to determine if these mutations are in Hardy-Weinberg equilibrium. METHODS AND RESULTS: Sixty-five patients with VT and 64 healthy volunteers were assessed for MTHFR 677T and 1298C alleles using polymerase chain reaction and restriction fragment length polymorphism. Observed MTHFR genotype frequencies were compared with expected genotype combinations, and their odds ratios were determined. MTHFR allele frequency did not differ between VT and control groups; however, differences were observed for MTHFR genotype distribution. MTHFR 677T and 1298C alleles occurred in cis in our population, and therefore mutation crossover has occurred. There was deviation from the Hardy-Weinberg equilibrium for combined MTHFR genotypes, although this may at least partly be attributable to linkage disequilibrium. MTHFR 677CT/1298CC and 677TT/1298CC genotypes (P<.05) were not observed in either group. CONCLUSIONS: The absence of MTHFR 677CT/1298CC and 677TT/1298CC genotypes in both groups suggests that certain MTHFR genotypes may carry a selective advantage. Our discovery of a substantial number of MTHFR mutations in cis configuration suggests that any MTHFR allele linkage disequilibrium present is incomplete.