Investigation of the effects of MTHFR gene variations and homocysteine levels in hypertensive patients.

Objective: To investigate the effects of methylenetetrahydrofolate reductase (MTHFR) gene C677T/A1298C polymorphisms on serum homocysteine levels and hypertension.

Methods: Venous blood samples were collected in EDTA tubes from patients and controls (80 hypertensive patients and 67 healthy controls) and genomic DNA was isolated. The polymorphisms of MTHFR C677T and A1298C were identified using the polymerase chain reaction (PCR) and restriction fragment length polymorphisms (RFLP) technique. The enzyme-linked immunosorbent assay (ELISA) method was used to determine serum homocysteine levels. ANOVA, Student's t-test, chi-square test and logistic regression analysis tests used in the evaluation of statistical analysis between patient and control groups were performed with SPSS 21.0 program.

Results: A statistically significant difference was observed between the patient group, which were hypertension-diagnosed patients, and control group for C677T polymorphism (p<0.001), but not for the A1298C polymorphism (p=0.058). When serum homocysteine levels were compared between the patient and control groups, no significant difference was observed (p=0.065). A significant difference was observed between C677T allele frequency (TT + CT versus CC) and homocysteine levels in both groups (p=0.027), whereas no significant difference was observed between A1298C allele frequency (CC + AC versus AA) and homocysteine levels (p=0.996).

Conclusion: The MTHFR C677T polymorphism is more common in hypertensive patients. T allele frequencies (CT and TT genotypes) and TT genotypes might increase the risk of hypertension and homocysteine levels. Although the A1298C C allele frequency (AC and CC genotypes) might increase the risk of hypertension, CC genotype distributions and homocysteine levels show no statistical significance on hypertension. C677T polymorphism is associated with hypertension thus it may be used as a potential biomarker.