Targeted Screening of Fabry Disease in Male Hemodialysis Patients in Brazil Highlights Importance of Family Screening

Introduction: Fabry disease (FD) is a lysosomal storage disorder caused by enzyme α galactosidase A (α-Gal A) deficiency due to mutations in the galactosidase alpha (GLA) gene. It leads to damage several organs, such as the kidneys, due to progressive accumulation of glycosphingolipids. Objective: To estimate the prevalence of FD among male hemodialysis (HD) patients in a northern state of Brazil. Methods: Screening was performed using a dried blood spot on filter paper to identify patients with low α-Gal A enzyme activity (≤2.2 µmol/l/h). Those with low enzyme activity underwent genetic analysis of the GLA gene. Family screening was conducted in the index cases. Results: 2,583 male HD patients (age: 52 (18-91 years)) were screened. The α-Gal A assay identified 72 males (2.78%) with low enzyme activity. Genotyping identified 3 patients with GLA mutations: W204X, A368T, both previously reported; and C52F, a novel missense mutation. Only the patient with W204X mutation had classic FD. The prevalence rate was 0.12%. Family screening of the index cases identified 23 family members with the same mutations. Conclusions: The prevalence of FD amongst male HD patients found in the Northern of Brazil was low (0.12%). However, family screening of the 3 index cases identified family members at an early stage of the disease, which may benefit from earlier treatment.