Objective: To study the relationships between polymorphisms of angiotensin-converting enzyme (ACE) gene and methylenetetrahydrofolate reductase (MTHFR) gene and pregnancy induced hypertension (PIH).
Methods: Ninety-nine PIH patients (PIH group), including 21 mild cases, 24 moderate cases and 54 severe cases and 54 normal pregnant women (control group) were recruited. The polymorphism of ACE gene was detected by PCR, and that of MTHFR gene was detected by PCR-RFLP.
Results: In PIH group, the frequencies of genotypes II, ID, and DD of ACE gene were 20.2%, 37.4% and 42.4% respectively, the frequencies of genotypes CC, CT, and TT of MTHFR gene were 53.5%, 31.3% and 15.2% respectively. There existed significant difference between genotypes DD, CT and D allele in PIH group and control group. Compared to mild PIH group, the frequencies of genotypes DD and CT in severe PIH group were significantly higher. The susceptibility to PIH in individuals with genotypes CC + DD was 2.648 times that of the controls. However, individuals with genotypes CT + II and CC + II were less susceptible to PIH in comparison to the controls. Logistic regression analysis showed that genotype DD and D allele were associated with PIH, genotype CT was associated with severe PIH.
Conclusion: Genotypes DD and CT may be the risk factors of PIH; genotype II may have a protective effect against PIH. There may exist some interaction between polymorphisms of ACE gene and MTHFR gene in the pathogenesis of PIH.