Even in Ander- son-Fabry disease, it has been difficult to adequately power studies to assess efficacy for stroke preven- Although in 1 German population the preva- lence of Fabry disease in young men with first-time cryptogenic ischemic stroke was reported to be as high as 2.17%,743 it appears that, for most popula- tions of young men with first-time cryptogenic stroke, the rate is <1%.744 The prevalence rate appears to be higher in young patients with recurrent cryptogenic ischemic stroke relative to young patients with first- time cryptogenic stroke.743 CLINICAL STATEMENTS AND GUIDELINES Kleindorfer Recommendation-Specific Supportive Text 1. An ecological study of a newborn screening pro- gram in Ireland supports the effectiveness of interventions to drive free homocysteine to 11 mmol/L to prevent thromboembolic events.739 A study of treatment of severe hyperhomocysteine performed in Australia, the Netherlands, and Ireland on patients who had cystathionine -synthase defi- ciency (mean age, 27.8 years; range, 2.5 70 years) supported a dramatic reduction of risk of vascu- lar events relative to a historical cohort study (RR, 2. 