The methylenetetrahydrofolate reductase (MTHFR) 677C>T and 1298A>C polymorphisms, which are associated with hyperhomocysteinemia and nitric oxide (NO) deficiency (which is related to atherothrombosis and cerebral ischemia), have not been studied in moyamoya disease.
We report a case of myocardial infarction at a young age in a subject heterozygous for the G20210A prothrombin gene variant and homozygous for the C677T MTHFR polymorphism, who presented a strong family history of atherothrombosis.