亚甲基四氢叶酸还原酶基因C677T多态性与冠心病的关联性研究

Association between Polymorphism of Methylenetetrahydrofolate Reductase C677T and Coronary Heart Disease

目的研究亚甲基四氢叶酸还原酶(MTHFR)C677T基因型和等位基因频率分布,探讨MTHFR基因多态性与湖北地区汉族人冠心病发病的关系。方法采用病例-对照研究方法,选取冠心病病例和与之年龄、性别匹配的对照各942例,应用实时荧光定量聚合酶链式反应(real time PCR)技术检测基因型,同时检测研究对象的空腹血清总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白(LDL)、高密度脂蛋白(HDL)、血压、身高、体重及腰围(WC)等临床参数,并计算体重指数(BMI)。结果冠心病组MTHFR(C677T)基因CC基因型频率为36.0%、CT基因型频率为45.0%、TT基因型频率为19.0%;正常对照组的3种基因型频率分别为36.7%、43.3%和20.0%。冠心病组MTHFR(C677T)基因各基因型分布频率与正常对照组相比差异均无统计学意义(均P>0.05)。Logistic回归分析结果提示,在吸烟者、活动少、有高血压史、糖尿病史和冠心病家族史的人群中患冠心病的危险性增加,反之则危险性降低。结论MTHFR(C677T)基因多态性与中国湖北地区汉族人患冠心病的危险性无关,可能不是冠心病遗传危险因素之一。

Objective To investigate the distribution of methylenetetrahydrofolate reductase （MTHFR） gene C677T genotypes and alleles in the Han nationality of Hubei province and the correlation between MTHFR polymorphism and coronary heart disease （CHD） risk. Methods In this case-control study, the MTHFR gene C677T polymorphism was detected by polymerase chain reaction （PCR）--real-time fluorescent quantitative PCR method in 942 CHD patients and age- and sex-frequencies matched 942 controls. Clinical parameters such as fasting serum total cholesterol （TC）, triglycerides （TG）, high density lipoprotein （HDL）, and low-density lipoprotein （LDL） were also determined. Blood pressure, weight, waist circle （WC）, and height were measured, and body mass index （BMI） was calculated. Results In CHD and control groups, the frequency of CC （homozygous normal）, CT （heterozygous）, and TT （homozygous mutant） was 36.0%, 45.0%, and 19.0%, and 36.7%, 43.3 % and 20.0 %, respectively. There was no significant difference in the genotype distribution and allele frequency of C677T polymorphism between two groups. The Logistic regression analysis suggested that smoking index, activity, past history of hypertension, diabetes or CHD could increase the risk of CHD. Conclusion There was no association between the MTHFR gene C677T polymorphism and CHD in Chinese Han nationality of Hubei province, indicating C677T in MTHFR gene was not a genetic risk factor of CHD.