N5,N10-亚甲四氢叶酸还原酶基因多态性及血浆同型半胱氨酸水平与心肌梗死的关系

研究N^5,N^10-亚甲四氢叶酸还原酶基因多态性及血浆同型半胱氨酸水平与心肌梗死的关系。运用多聚酶链反应-限制片长多态性技术检测178例心肌梗死患者及178例正常人N^5,N^10-亚甲四氢叶酸还原酶基因多态性，用高效液相色谱仪和荧光检测仪测定血浆总同型半胱氨酸水平。结果发现，N^5,N^10-亚甲四氢叶酸还原酶有3种基因型，即纯合子突变型（TT），杂合子突变型（TC）及正常型（CC），心肌梗死组TT型频率为35.4%，TC型频率为53.8%。CC型频率为10.8%。T等位基因频率为62.3%。C等位基因频率为37.7%，正常组中TT型频率为20.1%。TC型频率为55.8%。CC型频率为24.1%。T等位基因频率为32.1%,C等位基因频率为67.9%，且心梗死组TT高于正常组。正常人群中TT基因型者血浆总同型半胱氨酸水平明显高明于（TC CC）基因型者，心肌梗死患者血浆总同型半胱氨酸水平显著高于正常组，多因素分析显示，N^5,N^10-亚甲四氢叶酸还原酶基因突变型TT可能是心肌梗死发病一个危险因素，结论提示，N^5,N^10-亚甲四氢叶酸还原酶TT基因型突变可能升高个体血浆总同型半胱氨酸水平，N^5,N^10-亚甲四氢叶酸还原酶基因可能是心肌梗死的易感基因之一，N^5,N^10-亚甲四氢叶酸还原酶基因突变型TT及高同型半胱氨酸血症可能是心肌梗死发病的一个危险因素。

The Relationship of Polymorphisms of Methylenetetrahydrofolate (MTHFR) Gene and Plasma Homocysteine Levels with Myocardial Infarction

Aim To study the relationship of polymorphisms of methylenetetrahydrofolate (MTHFR) gene and plasma homcysteine (Hcy) levels with myocardial infarction. Methods 178 myocardial infarction patients and 178 normal subjects were recruited in the study. Their polymorphisms of MTHFR gene were analyzed using PCR RFLP and their plasma total Hcy levels were measured using high performance liquid chromatography with fluorescence detection. Results There were three kinds of genotype: TT (homozygous mutation), TC (heterozygous mutation) and CC (wild type). The frequencies of the three genotypes were as follows: TT, 35.4%; TC, 53.8%; CC, 10.8% in myocardial infarction patients and TT, 20.1%; TC 55.8%; CC, 24.1% in normal subjects, respectively. The frequency of T alleles was significantly higher in myocardial infarction patients than that in normal controls (62.3% and 37.7%, respectively). Mean total plasma homocysteine concentrations were significantly higher in myocardial infarction patients than in the normal subjects. Conclusions These results suggest that polymorphisms of MTHFR gene and hyperhomocysteinemia may be an independent risk factor for myocardial infarction.