Factor V Leiden, prothrombin gene G20210A variant, and methylenetetrahydrofolate reductase C677T genotype in young adults with ischemic stroke

Ischemic stroke in young adults is a well-known disease. but despite extens ive clinical and laboratory investigations, its etiology remains unclear in approximately half of the cases. We examined the prevalence of factor V Le iden, the prothrombin G20210A genotype, and the C677T mutation in the methy lenetetrahydrofolate reductase (MTHFR) gene in 100 patients (51 males and 4 9 females) who survived an ischemic stroke without a cardiac embolic source at an age less than or equal to 45 years, and in 238 healthy control subje cts from the same geographic area. The patients were selected for study onl y if the diagnosis of stroke was documented by computed tomography scan or nuclear magnetic resonance (NMR) of the brain, or both. Heterozygosity for the FV Leiden mutation was found in 3 patients (3.0%) and in 10 control sub jects (4.2%). Two patients (2.0%) and five control subjects (2.1%) were het erozygous for the prothrombin G20210A mutation. The frequencies of the MTHF R 677TT, CT, and CC genotypes in the patient group were 12%, 37%, and 51%, respectively, and were not significantly different from those in control su bjects (11%, 40%, and 49%, respectively). In conclusion, our results indica te that FV Leiden mutation, prothrombin G20210A genotype, and homozygosity for the C677T mutation in the MTHFR gene are not associated with an increas ed risk for ischemic stroke in young adults.