MTHFR基因多态性与冠心病的关系

目的研究天津地区人群N^5,N^10-亚甲基四氢叶酸还原酶（MTHFR）基因C677T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）的MTHFR基因C677T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浓度与叶酸水平呈显著负相关（r分别为-0.617和-0.588,P〈0.05）。结论MTHFR基因C677T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。

Relationship between methylenetetrahydrofolate reductase gene polymorphisms and coronary heart disease

Objective To study the relationship between methylenetetrahydrofolate reductase gene polymorphisms and coronary heart disease. Methods Fifty patients with coronary heart disease and 50 controls were studied, MTHFR gene C677T polymorphism was determined with polymerase chain reaction(PCR) and restriction fragment length polymorphism(RFLP). Plasma total homocysteine level was measured with high-performance liquid chromatography(HPLC) with fluorescence detection. Serum folate marked with 125I was determined by radio-immunology method. Results The frequency of MTHFR C677T homogenetic type and heterogenetic type in case group were 30% and 44% respectively, higher than those in the control group(20% and 28%). The frequency of the 677T allele in case group was much higher than that in the control group(P<0.05), plasma homocysteine levels were markedly higher in patients with TT genotype than those in patients with TC and CC genotype(P<0.05). There was an inverse relationship between homocysteine and folate in the case group and control group(r=-0.617 and-0.588 respectively,P<0.05). Conclusion MTHFR C677T gene polymorphism was closely associated with coronary heart disease.