Fabry disease and G6PD in three family members with priapism: is the nitric oxide pathway to blame?

Introduction: Fabry disease is an X-linked multisystem disorder due to alpha galactosidase A deficiency leading to glycosphingolipid accumulation with a predilection for the vascular endothelium and affecting the cardiovascular, renal, and neurologic systems.

Aim: To report a familial cluster of priapism in three males from a family with Fabry disease and glucose-6-phosphate dehydrogenase (G6PD) deficiency and discuss possible mechanisms.

Methods: Patient charts, Fabry registry, and literature review.

Results: Priapism has been reported in 6 males among the 1,558 males of the Fabry registry. Eight additional case reports of priapism in patients with Fabry disease and two reports of patients with G6PD were collected from the literature. Derangement in the nitric oxide (NO) pathway, which can occur in both Fabry disease and G6PD, is suggested as a hypothesis for the priapism in our patients.

Conclusions: It is suggested that priapism should be included in the list of clinical symptoms of Fabry patients and that Fabry disease should be added to the differential diagnosis of priapism. Furthermore, the association of G6PD and Fabry disease with priapism emphasizes the need for further study to explore the role of NO metabolism in the etiology of Fabry disease manifestations.