A renal variant of Fabry disease: A case with a novel Gal A hemizygote mutation.

BACKGROUND Fabry disease is caused by an X-linked recessive inborn error of glycosphingolipid metabolism with deficient activity of a lysosomal enzyme, alpha-galactosidase A (α-GalA). CASE PRESENTATION A 46 year-old man with progressive kidney disease showed on kidney biopsy electron microscopic evidence of Fabry disease. The patient had no systemic manifestations of Fabry disease, despite residual α-GalA activity, therefore genetic testing was done by direct DNA sequencing, demonstrating a new GAL A gene mutation (C174G-exon 3). After three years of enzyme replacement therapy (agalsidase beta) treatment, a second biopsy was done. Although there was demonstrable clearance of intracellular inclusions, remarkable podocyte activation was evident. CONCLUSIONS This report represents an unusual renal variant of Fabry disease and provides histologic data on long-term follow up after enzyme replacement therapy.