亚甲基四氢叶酸还原酶基因多态性与血浆同型半胱氨酸水平及青年急性缺血性卒中的相关性研究

目的 探讨同型半胱氨酸（homocysteine，Hcy）代谢酶N5，10-亚甲基四氢叶酸还原酶（N-5，10-methylene tertrahydrofolate reductase，MTHFR）基因多态性与血浆总同型半胱氨酸（total homocysteine，tHcy）水平及青年急性缺血性卒中的相关性。方法 采用病例-对照的方法，对40例青年急性缺血性卒中患者和40例健康体检者的病史和相关实验室检查资料进行记录，并应用高效液相色谱法测定血浆tHcy水平，采用聚合酶链-限制性内切酶片段长度多态性分析技术（polymerase chain reaction restriction fragment length polymorphism，PCR-RFLP），检测MTHFR C677T、A1298C基因型。结果 ①病例组MTHFR C677T基因突变率（77.5%）及T等位基因频率（53.8%）与对照组（75.0%和50.0%）相比，差异均无显著性（P＞0.05）；②病例组MTHFR A1298C基因突变率（32.5%）及C等位基因频率（17.5%）与对照组（17.5%和8.8%）相比，差异均无显著性（P＞0.05）；③血浆tHcy浓度在MTHFR C677T各基因型间的分布差异有显著性（P＜0.05）。结论 ①Hcy代谢酶MTHFR C677T、A1298C存在基因多态性；②MTHFR C677T基因突变（尤其是TT纯合型突变）可导致血浆tHcy浓度显著增高；③MTHFR C677T、A1298C基因多态性与青年急性缺血性卒中的发病无直接相关性。

Correlational Study Among the Polymorphism of MTHFR Gene, the Plasma tHcy Levels and Acute Ischemic Stroke in Young Adults

Objective To investigate the correlation among the metabolizing enzymes MTHFR of the homocysteine（Hcy）, tHcy levels and acute ischemic stroke in young adults. Methods Case-control method, 40 cases of acute ischemic stroke in young adults and 40 healthy persons were analyzed, we recorded their medical history and relevant laboratory examination data, measured the plasma tHcy levels with high performance liquid chromatography, determined the polymorphism of MTHFR C677T, A1298C by polymerase chain-restriction fragment length polymorphism（PCR-RFLP）. Results （1）The mutation rate and the T allele frequency of MTHFR C677T in case group were 77.5% and 53.8%, control group were 75.0% and 50.0%, and the change rate was no statistically significant between the two groups（P〉0.05）. （2）The mutation rate and the C allele frequency of MTHFR A1298C in case group were 32.5% and 17.5%, control group were 17.5% and 8.8%, and the change rate was no statistically significant between the two groups（P〉0.05）. （3）The distribution difference of the plasma tHcy concentration during the MTHFR C677T genotypes was statistically significant（P〈0.05）. Conclusions （1）The gene polymorphism of Hcy metabolism enzymes MTHFR C677T, A1298C was confirmed. （2）The gene mutation（especially the TT homozygous） of MTHFR C677T can increase the plasma tHcy concentration significantly. （3）There is no direct correction between the gene polymorphism of MTHFR C677T, A1298C and acute ischemic stroke in young adults.