Screening for Fabry disease in patients on Hemodialysis.

BACKGROUND

Fabry disease is an under-recognized X-linked lysosomal storage disorder characterized by the accumulation of trihexosylceramides in multifarious tissues, leading to end-organ damage, including progressive renal failure. Antecedent screening studies worldwide have shown inconsistent prevalence in the hemodialysis population. We conducted this study to screen for Fabry disease in patients undergoing dialysis at a tertiary care hospital.

MATERIALS AND METHODS

All patients undergoing dialysis were screened with a gal assay using dried blood spots (DBS) on filter paper using the fluorescence method. Patients with positive DBS test results were further tested for underlying mutations.

RESULTS

A total of 112 patients (64.3% males and 35.7% females) on dialysis were screened. Nineteen patients (13 males and 6 females) were found to have low enzyme activity on DBS. Further mutation analysis confirmed that one female patient had Fabry disease. The mutation detected was a heterozygous missense variation in exon 7 of the GLA gene, which resulted in the amino acid substitution of histidine for arginine at codon 363 (p.Arg363His). Subsequent screening of the family members revealed that the son of the patient was asymptomatic and carried the same genotypic mutation. Genetic counseling was performed, and enzyme replacement therapy was offered to both patients.

CONCLUSIONS

Fabry disease remains underdiagnosed, especially in high-risk populations such as those undergoing dialysis. DBS is a convenient and effective screening tool for Fabry disease. Facilities should be augmented for similar screening studies in the dialysis population.