Improvement in Cardiac Function in the Cardiac Variant of Fabry's Disease with Galactose-Infusion Therapy

Abstract
Fabry's disease is an X-linked inborn error of glycosphingolipid catabolism caused by deficient activity of α-galactosidase A, a lysosomal exoglycosidase.1,2 In males with the classic form of the disease, there is little if any α-galactosidase A activity. As a result, undegraded glycosphingolipids accumulate, particularly in the vascular endothelium. These deposits cause the characteristic angiokeratomas, acroparesthesias, hypohidrosis, and corneal opacities of Fabry's disease. Death in early adulthood in affected persons may be due to vascular disease of the heart, kidney, or brain. These abnormalities are absent in males with the cardiac variant of the disease. Those with the cardiac variant typically present with a mild, late-onset disorder that is primarily limited to the heart, and there is no involvement of the vascular endothelium.1-3 With advancing age, however, cardiac involvement progresses and leads to death.4 All of the previously described patients with the cardiac variant of Fabry's disease had mutations in the α-galactosidase A gene that encoded sufficient residual enzymatic activity to preclude the classic phenotype.1-3,5,6