Letter regarding Brouns et Al, Baptista et Al, and Wozniak et Al.

Stroke welcomes Letters to the Editor and will publish them, if suitable, as space permits. Letters must reference a Stroke published-ahead-of-print article or an article printed within the past 3 weeks. The maximum length is 750 words including no more than 5 references and 3 authors. Please submit letters typed double-spaced. Letters may be shortened or edited. Include a completed copyright transfer agreement form (available online at To the Editor: We congratulate the authors of the 3 recent studies addressing the prevalence of Fabry disease (FD) in stroke. 1–3 Previous studies provided conflicting results with no practical conclusion. 4,5 However, early diagnosis of FD could be crucial because enzyme replacement therapy may prevent severe disease manifestations. 6 The 3 studies differ according to populations enrolled. 1–3 Two studies considered ischemic or hemorrhagic strokes, 1,2 although the relation between FD and hemorrhagic stroke is unclear. Moreover, these 2 studies included patients regardless of stroke etiology, which may have led to underestimation of FD. The other study considered cryptogenic ischemic strokes only, but there was no definition for cryptogenic stroke. 3 Women were investigated in 2 studies only. 1,2 The studies also differed according to the method used for FD diagnosis. Screening for FD reliably can be performed by ␣-galactosidase A analysis in men, whereas gene mutation analysis is required in women. Although 2 studies used this approach, 1,3 the PORTYSTROKE study measured enzyme activity only in patients with identified gene mutation. 2 However, the pathological role of some polymor-phisms (eg, D313Y, which is associated with a pseudodeficient plasmatic activity) is uncertain. Interestingly, despite these differences, the results of the 3 studies are consistent: the prevalence of FD among stroke patients is low. Thus, using all available studies and excluding patients with D313Y mutation, the combined prevalence is 1.34% (95% CI, 0.21–3.42) in men and 1.45% (95% CI, 0.65–2.57) in women (Figure). 7,8 Hetero-geneity across studies is mainly accounted for by the Rolfs et al 4 study, which reported a high prevalence of enzymatic deficiency but no information on mutation analyses. The main practical implication of these findings is that the yield of screening for FD is low and that systematic screening in young stroke patients is not justified. However, the diagnosis of FD must not be missed because it has implications for the patient and family. Recent data of a FD registry found that 50% of men and 38% of women …