MTRR基因A66G多态性及血浆同型半胱氨酸水平与心肌梗死的关系

The relationship of polymorphisms of methionine synthase reductase gene and plasma homocysteine levels with myocardial infarction

目的研究MTRR多态性及血浆同型半胱氨酸(Hcy)水平与心肌梗死的关系。方法运用聚合酶链反应-限制性片段长度多态性技术(PCR-RFLP)检测180例心肌梗死患者及180例冠状动脉正常的人MTRR基因多态性,用高效液相色谱仪和荧光检测仪测定血浆总Hcy水平。结果 MTRR有3种基因型,即纯合子突变型(GG)、杂合子突变型(AG)及正常野生型(AA)。心肌梗死组GG型频率为35.4%,AG型频率为53.8%,AA型频率为10.8%,G等位基因频率为62.3%,A等位基因频率为37.7%。正常组中GG型频率为20.1%,AG型频率为55.8%,AA型频率为24.1%,G等位基因频率为32.1%,A等位基因频率为67.9%,且心肌梗死组GG型频率高于正常组(P<0.01)。正常人群中GG基因型者血浆总Hcy水平明显高于(AA+AG)基因型者(P<0.01)。心肌梗死患者血浆总Hcy水平显著高于正常组(P<0.01)。多因素分析显示,MTRR基因突变型GG可能是心肌梗死发病的一个危险因素。结论 MTRR GG基因型突变可能升高个体血浆总Hcy水平;MTRR可能是心肌梗死的易感基因之一;MTRR基因突变型及高Hcy血症可能是心肌梗死发病的一个危险因素。

Objective To study the relationship of polymorphisms of methionine synthase reductase（MTRR）gene and plasma homcysteine（Hcy）levels with myocardial infarction.Methods 180 myocaedial infarction patients and 180 coronary artery normal subjects were included in the study.The polymorphisms of their MTRR gene were analyzed by PCR-RFLP and their plasma total Hcy levels were measured by high-performance liquid chromatography and fluorescence detection methods.Results There were three kinds of genotype：GG（homozygous mytation）,AG（heterozygous mutation）and AA（wild-type）.The frequencies of the three genotypes were as follows：GG,35.4%;AG,53.8% and AA,10.8% in mypcardial indarction patients.Meanwhile,GG,20.1%;AG,55.8%;AA,24.1% in coronary artery normal subjects,respectively.The frequency of G alleles was significantly higher in myocardial infarction patients than that in normal controls（62.3% and 32.1%,respectively）（P〈0.01）.Mean total plasma homoctsteine concentrations were significantly higher in myocardial infarction patients than that in the normal subjects（P〈0.01）.Conclusion These results suggest that polymotphisms of MTRR gene and/or hyperhomocysteinemia may be an independent risk factor for myocardial infarction.