Methylenetetrahydrofolate reductase (MTHFR) catalyzes the conversion of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, a co-substrate for homocysteine re-methylation to methionine. Its deficiency leads to an increased serum level of homocysteine, which is well-known to be associated with premature coronary artery disease (CAD). Our case demonstrates the association of MTHFR polymorphism with premature CAD and myocardial infarction (MI) despite normal homocysteine levels. Screening for MTHFR polymorphisms in addition to homocysteine levels may be considered for patients presenting with premature CAD and a normal lipid profile. Aggressive risk reduction with lifestyle modifications and guideline-driven medical therapy supplementation might be necessary for secondary cardiovascular disease prevention until more specific therapeutic options are available for this subgroup of patients.
Keywords: coronary artery disease; mthfr; polymorphism.