MTHFR基因和β纤维蛋白原455G/A基因多态性与脑梗死的遗传易感性

MTHFR gene and β fibrinogen 455G/A gene polymorphisms and genetic predisposition to cerebral infarction

目的探讨MTHFR基因和β纤维蛋白原455G/A(βFib 455G/A)基因多态性与脑梗死的遗传易感性。方法运用PCR-RFLP检测154例脑梗死患者(脑梗死组)和83例健康体检者(对照组)MTHFR和βFib 455G/A基因多态性,同时检测纤维蛋白原(Fib)和血浆同型半胱氨酸水平等生化指标。结果脑梗死组患者MTHFR基因的CC、CT、TT基因型频率分别为21.4%、48.1%和30.5%,对照组分别为57.8%、25.3%和16.9%,脑梗死组TT基因型相对危险性为对照组的2.16倍;脑梗死组βFib 455G/A基因GG、GA、AA基因型频率分别为51.3%、40.3%和8.4%,对照组分别为72.3%、21.7%和6.0%。与对照组比较,脑梗死组患者GA基因型和A等位基因频率明显增高(P<0.05);具有CT+AA基因型或TT+GA基因型个体易患脑梗死,相对危险性为2.7和2.2。结论MTHFR基因突变后T等位基因和βFib基因突变后的A等位基因可能是脑梗死发生的一个遗传易感基因,MTHFR基因中CC型可能是脑梗死的保护因子,MTHFR基因和βFib 455G/A基因突变间可能存在协同作用。

Objective To study the relationships between methylene tetrahydrofolate reductase gene（MTHFR） and β fibrinogen 455G/A（βFib 445G/A） gene polymorphisms and occurrence of cerebral infarction. Methods The polymorphisms of MTHFR and 13 fibrinogen gene in 154 patients and 83 controls were analyzed using PCR-RFLP technology,the serum fibrinogen and total homocysteine levels were also measured. Results The frequencies of CC,CT and TT genotypes of MTHFR gene were 57.8% ,25.3%, 16.9% respectively in control group, and in cerebral infarction（CI） group the frequencies were 21.4% ,48.1% ,30.5%respectively. The relative risk ratio of TT genotype in CI group was 2.16 compared with that of control group. The frequencies of GG, GA and AA genotypes of βFib 445G/A gene were 51.3%,40.3% and 8.4% respectively in CI group,and in control group the genotype frequencies were 72.3%,21.7% and 6. 0%. Compared with control group, the frequencies of GA genotype and A allele were significantly increased in CI grouP. The individuals with CT＋AA or TT＋GA were more susceptable to CI in comparison with the controls,the relative risks were 2.7 and 2.2. The individuals with CC genotype were less predisposed to stroke. Conclusion T allele of MTHFR gene and A allele of βFib 455G/A gene may be the genetic susceptibility gene to CI,CC genotype of MTHFR gene may play a protective role. There may be synergic action between polymorphisms of MTHFR gene and βFib gene in pathogenesis of cerebral infarction.