ACE基因和MTHFR基因多态性对大脑中动脉狭窄协同影响的分析

ACE I/D with MTHFR 677CC genotype is an independent genetic factor that protects against middle cerebral artery stenosis： a community study in Foshan of China

目的探讨血管紧张素转换酶（ACE）基因I／D多态性和亚甲基四氢叶酸还原酶（MTHFR）基闪C667T多态性对广东社区无症状人群大脑中动脉狭窄（MCAS）的协同作用。方法整群采用随机数字表法抽取2500名社区居民进行流行病学问卷调查、人体学测量、生化指标以及经颅多普勒（TCD）等数据收集，筛选出符合人选标准的观察对象897人。依据大脑中动脉TCD检查的结果将其分为MCAS组和对照组。运用多聚酶链反应限制性内切酶片段长度多态性（PCR—RFLP）技术对ACE基因、MTHFR基因进行分型。通过前进法Logistic回归分析筛选出MCAS的独立影响因素。结果研究对象的性别、年龄、腰臀比以及Ⅱ＋CC基闲型的分布等因素在MCAS组和对照组中差异有统计学意义（P〈0．05），其中年龄和Ⅱ＋CC基因型进入了最终的Logistic回归方程而成为MCAS的独立影响因素。结论对广东社区无症状人群而言，ACE基因和MTHFR基因多念性对MCAS的影响存在协同作用，Ⅱ＋CC基因型对MCAS的发生具有保护作用。

Objective To explore the genetic interactions between angiotensin-converting enzyme （ACE） I/D and methylenetetrahydrofolate reductase （MTHFR） C677T genotypes in middle cerebral artery stenosis （MCAS） among the asymptomatic residents in Foshan area of China. Methods Using a cluster sampling method, 2500 subjects were randomly selected from the residential communities of Rongqi town of Foshan area, Guangdong Province. By means of epidemiological questionnaire survey, physical examination, examination of the biochemical markers and transcranial color Doppler （TCD）, 897 eligible subjects （306 males and 591 females） were selected from this population and subsequently divided into MCAS group and control group according to the TCD results. ACE and METHFR gene polymorphism analyses were conducted using amplified fragment length polymorphism-polymerase chain reaction （AFLP-PCR） and PCR-restriction fragment length polymorphism （PCR-RFLP）. Chi-square test, t test, Mann-Whitney test and logistic regression analysis were used to analyze the data. Results Gender, age, waist-to-hip ratio （WHR） and Ⅱ＋CC genotype distribution in the subjects with MCAS were significantly different from those in the control subjects. Logistic regression analysis identified age and ACE Ⅱ＋ MTHFR CC genotype as the independent factors that affected MCAS. Conclusion There are genetic interactions between ACE I/D and MTHFR C677T genotypes, and the ACE Ⅱ＋MTHFR CC genotype is an independent genetic factor for protection against MCAS in the asymptomatic residents in Foshan area of China.