中文摘要：

目的 探讨亚甲基四氢叶酸还原酶（MTHFR）C677T、A1298C2个位点基因多态性与缺血性脑卒中发病风险、疾病严重程度的相关性。评价同型半胱氨酸（Hcy）作为脑卒中血清危险因子的可行性。方法 选取初发缺血性脑卒中患者130例作为病例组,健康体检者100例作为健康对照组。采用实时荧光定量PCR方法分别检测2组MTHFR C677T和A1298C位点基因型。使用循环酶法测定2组血清Hcy水平。比较2组研究对象的基因型分布差异及Hcy水平差异。结果 病例组与健康对照组比较,C677T位点突变型（CT型＋TT型）所占比例显著增高（89.23%vs.56.00%）,差异有统计学意义（P〈0.05）;突变型等位基因T的分布频率比较（65.38%vs.44.00%）,差异有统计学意义（P〈0.05）;且随梗死面积增大,突变型所占比例明显增大。A1298C位点的突变频率在2组之间差异无统计学意义（P〉0.05）。病例组血清Hcy水平显著高于对照组[（16.15±9.71）μmol/L vs.（12.68±4.01）μmol/L,P〈0.05],且以大梗死组为最高。单一位点的突变与血清Hcy水平未发现显著的相关性。C677T与A1298C联合突变的比例,病例组显著高于对照组（16.15%vs.9.00%,P〈0.05）,且随梗死面积增大,联合突变者所占比例明显增大。在病例组内,2位点同时发生杂合突变时Hcy显著高于仅C677T杂合突变[（21.13±8.47）mol/L vs.（11.52±4.36）mol/L,P〈0.05）]。结论 血清Hcy水平升高会加大缺血性脑卒中的发病风险。MTHFR C677T基因发生突变可能是缺血性脑卒中的独立危险因素,且与疾病严重程度呈正相关。A1298C位点单独发生突变时与缺血性脑卒中的发生未发现相关性,但与C677T存在明显的协同作用,即2位点同时发生突变时,缺血性脑卒中的患病风险概率增加。

英文摘要：

Objeetive To explore the relationship between the polymorphisms of methylenetetrahydrofolate ruductase（MTHFR） gene and the risk of isehemic stroke（IS）. To investigate the correlation between the polymorphisms of MTHFR gene and plasma homocysteine（Hcy） levels in patients with IS. Methods 130 stroke patients and 100 healthy controls were collected. The polymorphisms were detected by real-time PCR, and the serum Hcy levels were measured by enzymatic cycling assay. Results In case group, the frequencies of mutant genotypes（CT＋TT）and T alleles were 89.23 % and 56.00% respectively, which were both signif- icantly higher than those of the control group（P〈0.05）. With the increase of infarct size, the proportion of mutant increased obvio usly（P〈0.05）, While there was no significant difference in mutation frequency of A1298C among each group （P〉0.05）. Serum Hcy levels in case group was significantly higher as compared with that of control group（P〈0.05）. There was a significant variation in the frequency of double heterozygote MTHFR 677CT/1298AC between IS patients and healthy people（P〈0. 05）. In addition, the frequency was higher along with the increment of infarction area Homocysteine levels were significantly higher in IS patients with the double heterozygote（P〈0.05） ;however, the difference was not significant with the single-site mutation. Conclusion Our results show a signifi- cant assqciation of HCy with the risk of IS. A correlation also seems to be observed between IS and the MTHFR C677T genotype frequencies , but riot in A1298C. However, a significant synergistic interaction was found with the double heterozygote MTHFR 677CT/1298AC.