The folate-sensitive polymorphism methylenetetrahydrofolate reductase (MTHFR) c. 677 C > T (A222V) referred a non-significant risk of ischemic stroke (odds ratio: 1.20) in all patients, and homozygosity for MTHFR c. 677 C > T was associated with an earlier onset of stroke selectively in patients younger than 60 years (38 +/- 3 years vs. 45 +/- 1 years; P = 0.043).