Prevalence of Fabry Disease and Outcomes in Young Canadian Patients With Cryptogenic Ischemic Cerebrovascular Events

Abstract

Background and Purpose— Previous studies reported Fabry disease in 0% to 4% of young patients with cryptogenic ischemic stroke (IS). We sought to determine the prevalence of Fabry and outcomes among young Canadians with cryptogenic IS or transient ischemic attack (TIA). Methods— We prospectively enrolled individuals aged 18 to 55 with IS or speech or motor TIA, and no cause identified despite predetermined investigation. α-galactosidase-A gene was sequenced for Fabry diagnosis. National Institutes of Health Stroke Scale score was measured at presentation to quantify stroke severity. Modified Rankin Scale determined functional outcomes ≤7 days after presentation and 6 months later. Results— We enrolled 365 patients with IS and 32 with TIA. α-galactosidase-A sequencing identified a single carrier of a genetic variant of unknown significance (p.R118C) and no well-recognized pathogenic variants. Mean National Institutes of Health Stroke Scale score was 3.1. Proportion of patients with modified Rankin Scale of 0 to 2 was 70.7% at ≤7 days and 87.4% at 6 months. National Institutes of Health Stroke Scale score at presentation and diabetes mellitus predicted 6-month modified Rankin Scale. Thirteen patients experienced 5 recurrent IS and 9 TIA during follow-up. No patient died. Most patients (98.7%) returned home. Among previous workers, 43% had residual working limitations. Conclusions— In this Canadian cohort of patients with cryptogenic IS or TIA, the prevalence of Fabry was 0.3% if p.R118C variant is considered as pathogenic. This suggests that more cost-effective methods should be applied for diagnosis of Fabry rather than systematic genetic screening in this population. Overall, cryptogenic IS in young adults is associated with favorable outcomes.