Methylenetetrahydrofolate Reductase C677t Gene Polymorphism and Homocysteine Levels Are Risk Factors for Myocardial Infarction

Increased plasma total homocysteine (tHcy) levels shown to be a risk factor for coronary artery disease (CAD). The common methylenetetrahydrofolate reductase C677T (MTHFR C677T) polymorphism has been reported to be a strong predictor of mild hyperhomocysteinaemia (HHcy). We assessed whether this mutation was associated with increased risk of myocardial infarction (MI) and plasma levels of tHcy. The study group consisted of 210 angiographically proven MI patients, and 202 age and sex matched healthy individuals as controls. MTHFR (C677T) gene polymorphism was detected based on the polymerase chain reaction and restriction digestion with HinfI. Total homocysteine plasma concentration was measured using immunoassay. T allele frequency was not found to be significantly higher in patients than in the control group: T vs. C was χ2=0.19, OR 1.0, CI 95% 0.8–1.4, p=0.6; and TT vs. CC was χ2=0.24, OR 1.2, CI 95% 0.6–2.3, p=0.6.We found significantly elevated levels of mean homocysteine in the patient group when compared to the control group (p =0.00). Our findings showed that MTHFR C677T polymorphism is not a risk factor for myocardial infarction in South Indian population and higher levels of homocysteine in patients indicated that the severity of the disease is independent of homocystein levels.