α-Galactosidase A deficiency in Dutch patients on dialysis: a critical appraisal of screening for Fabry disease

Introduction. Fabry disease or α-galactosidase A (α-Gal A) deficiency is an X-linked lysosomal storage disorder that often leads to renal insufficiency in males and occasionally in females. The disease is rare, but its prevalence may be underestimated due to its variable clinical picture. Enzyme supplementation therapy with rHu-αGal A is currently available. Limited experience has so far shown that therapy may at best stabilize renal function. Despite these preliminary findings, much effort is being put into screening high-risk groups for undiagnosed α-Gal A deficiency. We studied the prevalence of α-Gal A deficiency in a Dutch dialysis cohort to establish possible underdiagnosis. We discuss the benefits of screening for Fabry disease. Methods. Activity of α-Gal A in whole blood was measured in a group of 508 male Dutch dialysis patients. Results. Of the 508 patients studied only one patient, already known with Fabry disease, had a α-Gal A deficiency, a prevalence of 0.22% (95 CI 0–1.1%). Conclusions. No undiagnosed Fabry patients were found, indicating that in our studied cohort there is no large-scale underestimation of its prevalence. Even though screening of dialysis patients for Fabry disease might identify patients who remain otherwise unrecognized, screening of high-risk populations for α-Gal A deficiency should be carried out with caution since long-term efficacy of treatment is currently unknown.