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.

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 coronary heart disease patients and50controls 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 125 I was determined by radio-immunology method.Results:The frequence of MTHFR C677T homogenetic type and heterogenetic type in patients with coronary heart disease were30%and44%respectively,and was higher than those in control group(20%and28%,respectively).The frequency of677T allele was much higher than that in control group(P<0.05),and 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 correlation between homocysteine and folate in case group and control group(r=-0.617and-0.588,respectively,P<0.05).Conclusion:MTHFR C677T gene polymrophism was closely associated with coronary heart disease.