Renal transplantation between siblings with unrecognized Fabry disease.

Fabry disease is an X-linked lysosomal storage disease caused by deficiency of the lysosomal hydrolase, α-galactosidase A (α-Gal A). We report a case of a renal transplant recipient with unrecognized Fabry disease who received the allograft from a sibling donor with unrecognized Fabry disease. The recipient began to show a gradual increase of the serum creatinine with mild proteinuria at 3 years after transplantation. Histopathologic examination revealed finely vacuolated podocytes, demonstrated by ultrastructural examination to contain osmophilic myelin bodies. Furthermore, the recipient showed reduced circulating levels of α-Gal A and elevated urinary levels of globotriaosylceramide. These findings indicated that both the recipient and the donor suffered from Fabry disease of the renal variant phenotype. Enzyme replacement therapy (ERT) was initiated in the recipient, which resulted in a slight decrease of serum creatinine. Although mild proteinuria persisted, initiation of ERT in the recipient led to improvement of the renal function.