Association of the methylene-tetrahydrofolate reductase gene rs1801133 C677T variant with serum homocysteine levels, and the severity of coronary artery disease

Abstract This study aimed to investigate whether the single nucleotide polymorphism C677T (rs1801133) of the methylene-tetrahydrofolate reductase (MTHFR) gene was associated with the risk of coronary artery disease (CAD) and circulating homocysteine (Hcy) levels in Tunisian population. 310 angiografically diagnosed CAD patients and 210 controls were enrolled in this study. The MTHFR C677T (rs1801133) polymorphism was genotyped, and the Hcy concentrations were measured. The severity of CAD was evaluated using the Gensini scoring system. Compared to the CC genotype, the TT genotype confers a higher risk for CAD severity with an OR = 9.07 and 95% CI = 3.78–21.8. The T allele was the predisposing allele for CAD and that it was probably associated with CAD severity. The area under the ROC curve for Hcy was 0.764 (95% CI 0.660 to 0.868, p = 0.001). The receiver operating characteristics curve (ROC) for Hcy showed its useful prediction of CAD. Hcy levels were not significantly associated with CAD severity expressed by Gensini Score (GS). The MTHFR C677T (rs1801133) polymorphism influences circulating Hcy levels. The MTHFR C677T polymorphism and hyperhomocysteinemia could have an important role in the prediction of the presence and not the severity expressed by GS of CAD.