Huang Yining, Zhao Yl Yu lan, Li Shunwei
Department of Neurology, Peking Union Medical College Hospital, Chinese Academy OF Medical Science, Beijing 100730, China.
Zhonghua Yi Xue Za Zhi. 2002 Jan 25;82(2):119-22.
To investigate the relation between plasma homocysteine (Hcy) and cerebral ischemic diseases and that between polymorphism of methylenetetrahydrofolate reductase (MTHFR) gene and cerebral ischemic diseases.
The plasma homocysteine (Hcy) and genetic polymorphism of MTHFR among forty-nine cases with ischemic cerebral diseases, including 25 with acute cerebral infarction (CI) and 25 with transient ischemic attacks (TIA), were investigated. Fifty-five age- and sex-matched healthy persons were used as controls. All the subjects underwent brain CT, carotid duplex, transcranial Doppler examination, plasma Vitamin B(12) and folic acid examination, besides examination of plasma Hcy and nucleotide 677 MTHFR genotypes. The effects of age, liver function, renal function, smoking, drinking, plasma vitamin B(12), and folic acid were analyzed.
The mean plasma Hcy was significantly higher in the CI group and TIA group (17.4 +/- 7.6 micromol/L and 16.6 +/- 5.2 micromol/L) compared with that in the control group (12.6 +/- 5.2 micromol/L, P < 0.01). The odds ratio was 3.26 (95% CI, 1.05 approximately 10.09, P < 0.01). The Hcy concentration was significantly higher in persons with T/T genotype than in those with C/C or CT. There was no significant difference of frequency of mutant alleles (T) in site 677 of MTHFR gene and in frequency of homozygote T/T among the patients and controls (52.0% vs. 44.0%, P < 0.05 and 26% vs. 20.0%, P > 0.05). The difference of Hcy was significant between those being T/T homozygotic and those not being T/T homozygotic in different groups. There was no statistical correlation between plasma Hcy level and extra- and intracranial stenosis of cerebral artery. Increase of BUN and smoking were significantly correlated with increase of Hcy (P < 0.05). The concentrations of plasma Vitamin B(12) and folic acid were significantly correlated with that of Hcy.
Homozygote of mutant MTHFR gene C677T causes hyperhomocystinemia. There is a significantly association between hyperhomocystinemia and ischemic cerebrovascular disease. The frequency of mutation in MTHFR genotype is higher in Chinese than in Caucasians. In addition to gene mutation, renal function and smoking are related to increase of plasma Hcy. No correlation between genotype of MTHFR and stroke is found.
探讨血浆同型半胱氨酸（Hcy）与脑缺血性疾病的关系以及亚甲基四氢叶酸还原酶（MTHFR）基因多态性与脑缺血性疾病的关系。
对49例缺血性脑疾病患者进行血浆同型半胱氨酸（Hcy）及MTHFR基因多态性研究，其中急性脑梗死（CI）25例，短暂性脑缺血发作（TIA）25例。选取55例年龄、性别匹配的健康人作为对照。所有研究对象均进行头颅CT、颈动脉双功超声、经颅多普勒检查、血浆维生素B12及叶酸检查，同时检测血浆Hcy及MTHFR基因677位点核苷酸基因型。分析年龄、肝功能、肾功能、吸烟、饮酒、血浆维生素B12及叶酸对结果的影响。
CI组和TIA组血浆Hcy均值（17.4±7.6μmol/L和16.6±5.2μmol/L）显著高于对照组（12.6±5.2μmol/L，P<0.01）。优势比为3.26（95%CI，1.05～10.09，P<0.01）。T/T基因型者Hcy浓度显著高于C/C或CT基因型者。MTHFR基因677位点突变等位基因（T）频率及纯合子T/T频率在患者组与对照组间差异无统计学意义（52.0%对44.0%，P<0.05；26%对20.0%，P>0.05）。不同组T/T纯合子与非T/T纯合子Hcy差异有统计学意义。血浆Hcy水平与脑动脉颅内外狭窄无统计学相关性。血尿素氮升高及吸烟与Hcy升高显著相关（P<0.05）。血浆维生素B12及叶酸浓度与Hcy浓度显著相关。
MTHFR基因C677T突变纯合子导致高同型半胱氨酸血症。高同型半胱氨酸血症与缺血性脑血管病显著相关。中国人MTHFR基因型突变频率高于白种人。除基因突变外，肾功能及吸烟与血浆Hcy升高有关。未发现MTHFR基因型与脑卒中的相关性。
