MTHFR and myocardial infarction: Homocysteine, an amino acid generated via demethylation of dietary methionine, is associated with atherosclerosis and its complications, such as myocardial infarction and stroke.6,7 In fact, high concentrations of total homocysteine (tHcy) can lead to endothelial cell damage, impaired vascular compliance, and alterations of hemostasis.8 Besides an unhealthy lifestyle, poor diet, impaired renal function, and intake of certain drugs,9 moderate increases in tHcy have been associated with a 677C>T variant in the gene coding for methylenetetrahydrofolate reductase (MTHFR; OMIM 607093).10