Screening for Fabry disease among 619 hemodialysis patients in Saudi Arabia.

Objectives: To determine the prevalence of Fabry disease (FD) among Saudi patients on hemodialysis.

Methods: This prospective study was conducted in 3 major hospitals in the Kingdom of Saudi Arabia (KSA). All adult patients (greater than 18 years old) attending the dialysis unit who have end-stage renal disease (ESRD) and on hemodialysis were included. Known patients with FD and those who refused to participate in the study were excluded. All eligible patients were screened for FD using dry blood spot (DBS) for alpha-galactosidase A (α-Gal A). A positive DBS (enzyme activity less than 40%) was followed by another con rmatory enzyme assay. When the second DBS sample was also positive (enzyme activity less than 40%), a Sanger sequencing of the GLA gene was performed.

Results: A total of 619 patients with ESRD and on hemodialysis were screened for FD using DBS for α-Gal A enzyme level. Enzymatic activity was below 40% in 11 samples. On retesting, 3 females had less than 20% enzymatic activity suggesting FD. Sanger sequencing of these 3 females showed the variant c.1055C greater than G (p.Ala352Gly) confirming the diagnosis of FD. Family screening of one of these 3 patients revealed one asymptomatic female carrying the same variant.

Conclusion: The prevalence of FD in this cohort was 4.8 per 1000 patients. Screening of Fabry patients with ESRD seems to be a cost-effective strategy. Furthermore, relatives of the patients identified by screening enhances this screening strategy.