F2 and ischemic stroke: In a case-control study done by Saadatnia et al. on investigating the impact of prothrombin gene mutation on the incidence of ischemic stroke in Iranian youth, 76 people of 18 to 50 years of age without the classical risk factors for the stroke were taken for the study (22 cases and 54 controls) and recruited for 26 months in Al-Zahra hospital in Iran.