Objective: To study the relationships between polymorphisms of angiotensin-converting enzyme 1 (ACE-1) gene and N(5),N(10) -methylene-tetra-hydrofolic acid reductase (MTHFR) gene and ischemic stroke (IS).
Methods: The polymorphisms of ACE-1 and MTHFR genes in the peripheral white blood cells of 143 patients with IS and 154 controls were analyzed using PCR- RFLP.
Results: The frequencies of II, ID, and DD genotypes of ACE-1 gene were 37.1%, 48.3%, and 14.7% respectively in IS patients,and were 44.2%, 37.7%, and 18.2% respectively in the controls. The relative risk of stroke in IS group was 1.2 times that in the control group. The frequencies of TT, CT, and CC genotypes of MTHFR gene were 14.0%; 45.5%, and 40.5% respectively in the IS group, and 5.2%, 31.8%, and 63.0% respectively in the control group. The frequency of TT genotype was 5.2% in the control group and 1.4% in the IS group (P < 0.05). The frequency of T allele was 21.10% in the control group and 36.65% in the IS group (P < 0.01). The individuals with TT + ID or CT + ID were more susceptible to IS. The individuals with TT + ID were 4.3 times susceptible to IS than the controls, and the individuals with CT + ID were 1.63 times susceptible to IS than the controls. However, the individuals with CC + ID were less susceptable to IS in comparison to the controls (P = 0.003).
Conclusion: TT and CT genotypes of MTHFR gene may be the risk factors of IS. There is a co-effective action between polymorphisms of ACE-1 gene and those of MTHFR gene in the pathogenesis of IS. CC genotype may have a protective effect against IS.