MTHFR C677T、CBS 844ins68基因多态性与潍坊市城乡居民H型高血压的关系

目的探讨亚甲基四氢叶酸还原酶MTHFR C677T、胱硫醚-β-合成酶CBS 844ins68基因多态性与潍坊市城区、农村居民H型高血压的关系,以进一步了解H型高血压发病的遗传学机制。方法采用聚合酶链反应-限制性片段长度多态性(PCR-RFLR),对潍坊市城区740名和农村800名成年人(包括高血压患者),进行MTHFR C677T、CBS 844ins68基因型分型和血浆同型半胱氨酸(Hcy)水平检测。结果所调查的人群高同型半胱氨酸血症患者城区、农村分别占55.81%、35.63%,城区高Hcy(10μmol/L)者413人(55.81%),农村285人(35.63%),城区高于农村(P0.01);城区H型高血压患病率(25.27%)高于农村(11.75%)(P0.01);城区组MTHFR C677T基因TT、CT、CC基因频率分别为41.62%、47.16%、11.22%,农村组为25.88%、58.75%、15.38%,差异有统计学意义(P0.01);高血压人群中,MTHFR C677T基因TT基因型的Hcy水平(15.17±5.37μmol/L)高于CC+CT基因型(9.71±5.81μmol/L),(P0.01),TT基因型H型高血压患者的比例(71.81%)高于CC+CT基因型(38.68%)(P0.01);CBS 844ins68DD、DI基因型在城市、农村间人群基因型和等位基因频率分布、高血压人群Hcy水平及H型高血压患者比例,差异无统计学意义(P0.05)。结论潍坊市居民的MTHFR C677T基因型频率、Hcy水平、H型高血压患病率存在城乡差异,MTHFR C677T基因纯合突变可能是引起Hcy水平升高,进而引发H型高血压的重要遗传因素,CBS 844ins68基因多态性与H型高血压无明显相关。     

同型半胱氨酸和胱硫醚-β合成酶基因多态性与脑梗死的关系

目的探讨同型半胱氨酸(Hcy)和胱硫醚-β合成酶(CBS 844ins 68)基因多态性与脑梗死的关系。方法运用多聚酶链反应技术和荧光偏振法(FPIA)检测75例脑梗死及143例正常人CBS 844ins 68基因多态性和血浆总Hcy水平。结果①脑梗死组CBS844ins 68 D/D、D/I、I/I基因型频率(%)分别为80.00、17.33、2.67,对照组分别为78.32、18.88、2.8,CBS844ins 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>005)。②脑梗死组与对照组血浆Hcy分别为(13.6±5.4)μmol/L和(10.9±2.4)μmol/L,两者有显著性差异(p<0.05)。脑梗死患者血浆总Hcy水平显著高于正常组。结论胱硫醚-β合成酶多态性与脑梗死无明显相关,高同型半胱氨酸血症与脑梗死发生有一定关系。     

孕期环境危险因素以及母亲MTHFR677C→T、血浆Hcy与儿童先天性心脏病的关系

目的:分析儿童不分型先天性心脏病(CHD)致病的危险因素,探讨CHD与母亲亚甲基四氢叶酸还原酶(MTHFR)677C→T和血浆同型半胱氨酸(Hcy)的相关性。方法:采用病例对照研究方法,分析80对CHD患儿与对照儿父母所处的环境因素并检测其MTHFR677位点的多态性和血浆Hcy的水平,进行单因素及多因素Logistic回归分析。并且通过母子配对,分析MTHFR677位点多态性和血浆Hcy水平与CHD发生的相互关联。结果:①母孕早期发烧(OR=4.465)、孕期居住乡村(OR=2.234)、孕期吸烟环境(OR=20.529)、母子血浆Hcy水平增高(OR=3.342,OR=3.069)为不分型CHD的危险因素。②儿童与母亲MTHFR677位点基因型之间没有明显的关联,双方血浆Hcy水平亦无明显关联(P均>0.05)。③病例组与对照组MTHFR677位点基因型差异无统计学意义(P>0.05),病例组母子血浆Hcy水平均显著高于对照组相应值(P均<0.01)。结论:①母孕早期发烧、孕期居住乡村、孕期吸烟环境、母子血浆Hcy水平增高为不分型CHD的危险因素。②MTHFR基因677C→T对血浆Hcy水平影响有待于进一步研究。③在CHD发生上,母子MTHFR基因677位点基因型之间和血浆Hcy水平之间均没有相关性。     

亚甲基四氢叶酸还原酶C677T基因多态性与2型糖尿病下肢血管病变

目的探讨亚甲基四氢叶酸还原酶(methylenetetrahydrofolate reductase,MTHFR)基因C677T多态性与2型糖尿病(T2DM)下肢血管病变的关系。方法选取344例T2DM患者和159名健康志愿者(对照组),其中T2DM患者分为两个亚组,糖尿病合并下肢血管病变组(DM+PAD组)176例和单纯糖尿病组(DM组)168例,检测3组同型半胱氨酸水平,采用PCR-芯片杂交技术检测亚甲基四氢叶酸还原酶C677T多态位点基因型,计算等位基因频率并统计分析。结果 DM+PAD组MTHFR基因纯合基因型(TT)、杂合基因型(CT)及T等位基因频率分别为11.4%、35.2%和29.0%,均明显高于DM组(分别为5.9%、27.4%和20.6%)和对照组(分别为3.1%、28.9%和17.6%),基因型和等位基因频率分布差异均有统计学意义(P0.05),而DM组和对照组之间的分布差异无统计学意义(P0.05)。单因素Logistic回归分析结果显示,MTHFR基因型C677T多态性与糖尿病下肢血管病变的发生密切相关(OR值及其95%CI分别为1.760、1.048~2.755)。携带T等位基因患者血中Hcy水平显著高于未携带T等位基因患者,差异有统计学意义(P0.01)。结论 MTHFR基因C677T多态性与北京地区2型糖尿病患者下肢血管病变相关,同型半胱氨酸的升高可能参与了下肢血管病变的发生与发展。     

荆州地区同型半胱氨酸及其代谢酶基因多态性与不良孕产史之间的关系

目的 探讨亚甲基四氢叶酸还原酶(5,10-Methylenetetrahydrofolate reductase,MTHFR)和甲硫氨酸合成酶还原酶(Methionine synthase reductase,MTRR)基因多态性及血浆同型半胱氨酸(Homocysteine,Hcy)水平与不良孕产史之间的关系。方法 采用病例对照研究方法,收集有不良孕产史的孕妇100名做为病例组,同时选取无不良孕产史的孕妇100名做为对照组。采用Taqman-MGB技术检测口腔黏膜上皮细胞MTHFR基因C677T,A1298C和MTRR基因A66G位点基因多态性;循环酶法测定血浆Hcy浓度。结果 200名孕妇中,MTHFR基因C677T位点T等位基因频率分布为41. 5%,A1298C位点C等位基因频率为20. 8%,MTRR基因A66G位点G等位基因频率为27. 5%。两组人群相比,MTHFR基因C677T,A1298C和MTRR基因A66G位点基因多态性分布差异无统计学意义(P0. 05)。200名孕妇血浆Hcy平均水平为(5. 09±1. 72)μmol/L,不同基因型孕妇血浆Hcy水平差异无统计学意义(P0. 05)。与对照组相比(4. 76±1. 71)μmol/L,病例组(5. 43±1. 67)μmol/L血浆Hcy水平显著升高,且差异具有统计学意义(P 0. 05)。Logistic回归分析显示,孕妇血浆Hcy水平每升高一个单位,不良孕产发生的风险增加0. 27倍(OR=1. 27,95%CI:1. 07～1. 52,P 0. 05);同样以血浆Hcy水平中位数5. 23μmol/L为界值,经Logistic回归分析显示,血浆Hcy水平较高的孕妇不良孕产发生风险是Hcy水平较低孕妇的1. 25倍(OR=2. 25,95%CI:1. 28～3. 96,P 0. 05)。结论 荆州地区孕妇Hcy代谢相关酶基因MTHFRC677T、A1298C和MTRRA66G位点基因多态性与不良孕产史无明显关联,但血浆Hcy水平升高是不良妊娠发生的重要危险因素。     

MTHFRC677T基因多态性与胎儿神经管畸形关系

目的:探讨亚甲基四氢叶酸还原酶(MTHFR)C677T位点基因多态性与胎儿神经管畸形的相关性。方法:分别选择52例既往孕有神经畸形胎儿的女性(观察组)和50例正常孕育史女性(对照组),取肘静脉血采用TaqMan探针SNP基因分型技术检测MTHFR C677T位点基因多态性,循环酶法检测血清同型半胱氨酸Hcy水平。分析MTHFR C677T位点基因多态性与血清Hcy水平以及胎儿神经管畸形易感的相关性。结果:观察组MTHFR C677T位点TT基因型、等位T基因频率高于对照组(P0.05)。观察组MTHFR C677T位点TT基因型受试者血清Hcy水平高于CC、CT基因型者(P0.05);对照组MTHFR C677T位点3种基因型之间差距没有统计学意义(P0.05)。二元logistic回归分析MTHFR C677T位点TT基因型[OR=2.003(95%CI:1.245～5.235)]携带者是胎儿神经管畸形易感的危险因素(P0.05)。结论:MTHFR C677T位点携带TT基因型人群血清Hcy水平偏高,是胎儿神经管畸形易感的高危人群。     

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。     

血浆同型半胱氨酸水平及亚甲基四氢叶酸还原酶基因突变与脑卒中关系的病例对照研究

目的 探讨中国人脑卒中与血浆同型半胱氨酸(Hcy)水平及N~5N~(10)亚甲基四氢叶酸还原酶(MTHFR)基因突变的关系。方法 收集脑卒中患者300例为病例组,选择300名性别、年龄和种族等与病例组相匹配的无脑卒中者作为对照组,采用高效液相色谱的方法检测两组的血浆Hcy水平,并通过聚合酶链反应和限制性酶切的方法对其MTHFR C677T基因型进行鉴定,统计分析血浆Hcy水平与脑卒中的关系,以及MTHFR C677T基因突变与脑卒中发生的关系及其对血浆Hcy水平的影响。结果 脑卒中组血浆Hcy水平显著高于对照组[(16`92±3.43)μmol/L vs.(14.57±2.59)μmol/L,P<0.05];MTHFR C677T基因突变率在脑卒中组与对照组之间差异无统计学意义(P>0.05),在脑溢血和脑梗死组之间差异也无统计学意义(P>0.05);MTHFR C677T基因变异对血浆Hcy水平无明显影响[(15.28±2.17)μmol/L vs.(15.11±3.81)μmol/L,P>0.05]。结论 血浆Hcy水平升高在中国人脑卒中的发生中起着重要的作用,而Hcy代谢过程中的关键酶MTHFR基因的C677T突变与血浆Hcy水平无明显关系,而且与脑卒中的发生无相关性,因此控制血浆Hcy水平在预防心脑血管疾病的发生中有重要意义。     

如皋市H型高血压患者MTHFR C677T基因多态性与同型半胱氨酸水平分析

目的探讨H型高血压患者的亚甲基四氢叶酸还原酶(MTHFR)C677T基因多态性与血清同型半胱氨酸(Hcy)水平。方法对H型高血压患者进行MTHFR C677T基因分型检测,并对各基因型患者高Hcy水平进行统计分析。结果 310例H型高血压患者中MTHFR C677T基因CC型、CT型、TT型分别占22.90%(71例)、45.48%(141例)、31.62%(98例)。CC型患者Hcy水平为(20.82±8.83)μmol/L,CT型患者为(20.99±13.14)μmol/L,TT型患者为(25.17±13.01)μmol/L。TT型患者血清Hcy水平高于CC型和CT型患者(P值均0.05),且TT型男性患者Hcy水平高于女性(P0.05)。结论 H型高血压患者中TT型患者Hcy水平较高,对高血压患者进行MTHFR C677T基因检测,对降低心脑血管病的发病率有着十分重要的意义。     

CBS基因甲基化对叶酸干预HHcy效果的性别特异性研究

目的 探究胱硫醚β合成酶(CBS)基因启动子甲基化在不同性别中对叶酸干预高同型半胱氨酸血症(HHcy)效果的影响。 方法 研究对象选自郑州大学第五附属医院住院的1 071例HHcy患者，进行90天的口服叶酸(5 mg/d)干预治疗。根据治疗后复查的血浆同型半胱氨酸(Hcy)水平将患者分为未达标组(Hcy≥15 μmol/L)和达标组(Hcy<15 μmol/L)。运用MethylTargetTM目标区域甲基化测序法检测299例患者CBS基因甲基化水平。运用多因素logistic回归分析CBS基因甲基化在不同性别中对叶酸干预HHcy效果的影响。运用受试者工作特征曲线(ROC)分析CBS基因甲基化在不同性别中对HHcy疗效的预测效果。 结果 CBS基因甲基化水平在两组间的分布差异仅在男性中有统计学意义( t =2.428， P =0.016)。较低水平的CBS基因甲基化在男性中能显著增加叶酸干预HHcy未达标的风险( OR =2.63, 95% CI : 1.41~4.92)。男性患者中CBS基因甲基化与HHcy疗效的ROC曲线下的面积为0.60 (95% CI : 0.52~0.68)。在女性患者中，基因甲基化与HHcy疗效的关联无统计学意义( OR =1.09，95% CI : 0.50~2.37)。 结论 CBS启动子甲基化对叶酸干预HHcy效果的影响存在性别特异性。     

Polymorphisms of key enzymes in homocysteine metabolism affect diet responsiveness of plasma homocysteine in healthy women

High plasma total homocysteine (tHcy), low dietary intake of folate and other B vitamins, and genetic polymorphisms related to metabolism of homocysteine may interactively contribute to the risk of cardiovascular disease. We investigated whether known mutations in genes regulating homocysteine metabolism affect the responsiveness of serum folate and plasma tHcy to high intake of natural folate from food. Healthy females (n = 37) aged 22-57 y volunteered to participate in a crossover dietary intervention with two 5-wk diet periods (low and high folate diets). Concentrations of serum and RBC folate, serum vitamin B-12 and plasma tHcy were measured at baseline and at the end of each diet period. The prevalences of C677T transition of methylenetetrahydrofolate reductase (MTHFR) gene, 844ins68 of cystathionine beta-synthase (CBS) gene and A2756G mutation of methionine synthase (MS) gene were determined. Compared with the low folate diet, the high folate diet increased the serum folate concentration by 85% (P < 0.001), 77% (P < 0.001) and 55% (P < 0.05) in the subjects with the genotypes C/C (n = 19), C/T (n = 13) and T/T (n = 5), respectively, of the MTHFR gene. Also, the plasma tHcy of the subjects with the genotypes C/C, C/T and T/T was decreased by 11% (P < 0.001), 15% (P < 0.01) and 18% (P < 0.05), respectively, during the high folate diet period. The subjects carrying the G2756 allele of the MS gene (n = 15) had a more extensive reduction (P < 0.05) of plasma tHcy during the high folate diet period than the subjects with the genotype A/A (n = 22). The 844ins68 of CBS gene did not affect plasma tHcy concentrations or diet responsiveness. In conclusion, diet responsiveness of plasma homocysteine may be genetically regulated.     

No association between common polymorphisms in genes of folate and homocysteine metabolism and the risk of Down's syndrome among French mothers

The cause of the non-disjunction leading to trisomy 21 remains unclear. Recent evidence has suggested that 5,10-methylenetetrahydrofolate reductase (MTHFR) and/or methionine synthase reductase (MTRR) might contribute to the maternal risk of trisomy 21. The purpose of the present study was to analyse these findings among the French population and to investigate whether common polymorphisms in genes of the folate and homocysteine pathway, including the MTHFR 677C > T, MTHFR 1298A > C, the methionine synthase (MTR) 2756A > G, the cystathionine beta-synthase (CBS) 844Ins68 and the reduced folate carrier (RFC-1) 80G > A polymorphisms, contribute to the risk of trisomy 21. The risk was studied by analysing independent and combined genotypes in 119 case mothers and 119 control mothers. The MTHFR 677T, MTHFR 1298C, MTR2756G, MTRR66G, CBSIns68+ and the RFC-1 80G allele frequencies were not significantly different among French case mothers, compared with control mothers. The risk of having a child with trisomy 21 did not appear to be linked to polymorphisms in genes associated with folate and homocysteine metabolism.     

MTHFR基因、CBS基因、环境因素与先天性心脏病的病例对照研究

目的 探讨父母亚甲基四氢叶酸还原酶（MTHFR）基因C677T、胱硫醚β-合酶（CBS）基因T833C、环境因素与子代先天性心脏病（CHD）发生之间的关联。方法 采用1：1配对病例对照研究方法，分析115对CHD患儿与对照儿父母的环境暴露因素，并检测其MTHFR与CBS基因型，对CHD可能的危险因素进行单因素及多因素条件logistic回归分析。结果 母亲怀孕早期接触农药（OR=8．62）、妊娠合并症（OR=2．069）、孕早期感冒（OR=4．125）、孕期情绪状况（OR=4．653）、母亲MTHFR基因677TT型（OR=3．872）共5个因素为予代发生CHD的危险因素。结论 母亲MTHFR基因677TT型与子代CHD发生有关，未发现父母CBS基因T833C与子代CHD存在关联，母亲怀孕早期接触农药、妊娠合并症、孕早期感冒、孕期情绪紧张或忧郁可能增加子代发生CHD的危险。     

Dietary and genetic determinants of homocysteine levels among Mexican women of reproductive age

OBJECTIVE: To evaluate the independent and joint effects of dietary folate, vitamin B(12) consumption and methylenetetrahydrofolate reductase (MTHFR) polymorphisms (677C>T and 1298A>C) on the circulating folate and homocysteine (Hcy) levels among Mexican women of reproductive age. DESIGN: A cross-sectional, population-based study. SUBJECTS: The first 130 healthy non-pregnant women (aged 16-34 years) who agreed to participate in a reproductive cohort in Morelos, Mexico. MAIN OUTCOME MEASUREMENTS: Dietary intakes of vitamin B(12) and folate were estimated using a semiquantitative food frequency questionnaire. MTHFR 677C>T and 1298A>C polymorphisms were ascertained using the PCR-based method. Serum levels of Hcy and folate were determined using high-performance liquid chromatography and radioimmunoassay, respectively. RESULTS: Genotype frequencies for the MTHFR 677C>T polymorphism were 21.5% (CC), 52.3% (CT) and 26.2% (TT) among Mexican women. Of the population, 22% had the MTHFR 1298AC genotype, while no individual carried the 1298CC genotype. We observed an increased level of Hcy among carriers of the 677TT genotype, compared to carriers of the 677CC genotype. The highest level of Hcy was observed among MTHFR 677TT carriers with low B(12) intake (<2.0 microg/day), which resulted with a significant interaction (P=0.01). CONCLUSION: Vitamin B(12) is an important determinant of Hcy levels in Mexico. Supplementation of folic acid with vitamin B(12) may be preferable when the MTHFR 677T variant allele is prevalent.     

MTHFR基因C677T位点多态性与胎儿生长受限的相关性

目的:探讨亚甲基四氢叶酸还原酶(MTHFR)基因C677T位点多态性与胎儿生长受限(FGR)的关系。方法:FGR患者62例,正常妊娠妇女65例。聚合酶链反应—限制性内切酶片段长度多肽性(PCR-RFLP)法检测MTHFR C677T基因多态性;荧光偏振免疫法测定血浆总同型半胱氨酸水平;微粒子酶免分析法测定血浆叶酸、VitB12浓度。结果:①FGR组MTHFR C677TC/T基因型频率显著高于正常对照组,C/C基因型频率显著低于对照组,总的突变T等位基因频率显著高于对照组(P<0.05)。②FGR组MTHFRT/T基因型Hcy水平较C/C、C/T基因型患者显著增高,而血清叶酸水平则明显降低(P<0.05)。血清VitB12水平在FGR3种基因型之间差异无显著性(P>0.05)。对照组MTHFR C677T3种基因型之间血清Hcy、叶酸、VitB12,水平差异无显著性(P>0.05)。结论:MTHFR基因C677T位点多态性与FGR有关,高同型半胱氨酸血症是FGR发病的危险因素。     

孕期生活事件及亚甲基四氢叶酸还原酶基因多态性与子代先天性心脏病的关联

目的探讨孕期应激性生活事件、亚甲基四氢叶酸还原酶(MTHFR)基因C677T多态性及其交互作用与子代先天性心脏病的关系。方法采用以医院为基础的病例对照研究设计,按照纳入和剔除标准选择144例病例与168例对照,对母亲进行问卷调查,收集人口统计学信息、孕期健康状况、孕期生活事件;并收集静脉血,通过聚合酶链反应—限制性片段长度多态性(polymerase chain reaction restricted fragmentlength polymorphism,PCR-RFLP)检测MTHFR C677T基因型。采用单因素和多因素非条件logistic回归模型,进行影响因素关联强度及交互作用分析。结果病例组和对照组一般情况指标差异无统计学意义。应激性生活事件阳性与子代先心病发生有关联,其OR值分别为2.248(95%CI:1.139～4.433),调整混杂因素后,OR值为2.851(95%CI:1.624～4.981)。两组MTHFR 677TT基因型频率和T等位基因频率的差异有统计学意义(χ2=22.38,P<0.001;χ2=20.36,P<0.000 1),MTHFR 677TT基因型与先心病风险的OR为3.215(95%CI:1.958～5.280);MTHFR 677TT基因型与应激性生活事件阳性之间具有正相加交互作用,调整混杂因素前后,TT基因型与应激性生活事件阳性的I(AB)为6.521、7.324,AP(AB)为35.5%、42.2%,AP*(AB)为40.8%、52.4%。结论孕期应激性生活事件阳性是子代先心病发生的危险因素;MTHFR 677TT基因型是先心病的易感因素;MTHFR 677TT基因型与孕期应激性生活事件对先心病具有协同作用。     

Prevalence and effects of gene-gene and gene-nutrient interactions on serum folate and serum total homocysteine concentrations in the United States: findings from the third National Health and Nutrition Examination Survey DNA Bank

BACKGROUND: Abnormalities of folate and homocysteine metabolism are associated with a number of pediatric and adult disorders. Folate intake and genetic polymorphisms encoding folate-metabolizing enzymes influence blood folate and homocysteine concentrations, but the effects and interactions of these factors have not been studied on a population-wide basis. OBJECTIVE: The objective was to assess the prevalence of these genetic polymorphisms and their relation to serum folate and homocysteine concentrations. DESIGN: DNA samples from 6793 participants in the third National Health and Nutrition Examination Survey (NHANES III) during 1991-1994 were genotyped for polymorphisms of genes coding for folate pathway enzymes 5,10-methylenetetrahydrofolate reductase (MTHFR) 677C-->T and 1298A-->C, methionine synthase reductase (MTRR) 66A-->G, and cystathionine-beta-synthase 844ins68. The influence of these genetic variants on serum folate and homocysteine concentrations was analyzed by age, sex, and folate intake in 3 race-ethnicity groups. RESULTS: For all race-ethnicity groups, serum folate and homocysteine concentrations were significantly related to the MTHFR 677C-->T genotype but not to the other polymorphisms. Persons with the MTHFR 677 TT genotype had a 22.1% (95% CI: 14.6%, 28.9%) lower serum folate and a 25.7% (95% CI: 18.6%, 33.2%) higher homocysteine concentration than did persons with the CC genotype. Moderate daily folic acid intake (mean: 150 microg/d; 95% CI: 138, 162) significantly reduced the difference in mean homocysteine concentrations between those with the MTHFR 677 CC and TT genotypes. We found a significant interaction between MTHFR 677C-->T and MTRR 66A-->G on serum homocysteine concentrations among non-Hispanic whites. CONCLUSIONS: The MTHFR 677C-->T polymorphism was associated with significant differences in serum folate and homocysteine concentrations in the US population before folic acid fortification. The effect of MTHFR 677C-->T on homocysteine concentrations was reduced by moderate daily folic acid intake.     

四川南充市健康体检者同型半胱氨酸代谢酶基因多态性分布及其水平关联

目的 研究南充市汉族人群同型半胱氨酸(Hcy)代谢关键酶基因多态性的分布及与Hcy水平的关联.方法以在南充市中心医院的汉族人群470人为研究对象,抽取受检者血样,收集研究对象一般临床资料,采用循环酶法测定血浆Hcy水平,提取基因组DNA后进行SNP基因多态性检测,分析Hcy代谢关键酶MTHFR C677T、MTHFR ...     

中国北方少数民族人群同型半胱氨酸代谢酶的遗传多态性

目的 了解我国北方地区3个少数民族人群中MTHFR和CBS基因的遗传多态性,获得MTHFR C677T和A1298 C 以及CBS T833C和G919A位点的群体遗传学数据。方法 应用PCR-RFLP,PCR-ARMS技术分别调查了吉林延边朝鲜族、新疆乌鲁木齐维吾尔族和回族新生儿的基因型分布。结果 回族和朝鲜族MTHFR677纯合突变频率为16.7％和20.9％,与中国北方人群的总体水平基本一致,而维吾尔族人群纯合突变频率(5.3％)低于其它民族,但差异无显著性(P>0.05);朝鲜族人群CBS基因T833 C纯合突变频率(7％)低于其它两个民族(15.8％～16.7％)。结论 CBS T833 C位点多态性也可能存在群体差异。