Study to Collect Data on Fabry Disease Patients With Enhanceable Alpha-Galactosidase A Activity

This protocol is designed to characterize the clinical and laboratory profile of patients with Fabry disease who have residual levels of Alpha-galactosidase (Alpha- Gal A) activity. Normally these are patients with the later onset or milder forms of the disease, sometimes referred to as the cardiac and/or renal variants. Enzyme Enhancement Therapy is a novel therapeutic approach to treatment of lysosomal storage diseases that has recently been proposed, for patients who produce low levels of endogenous enzyme. We plan to evaluate this therapy in later-onset Fabry disease patients and in preparation we need to develop sensitive outcome measures for this subset of patients. Thirty patients with enhanceable Alpha- Gal A activity will be recruited. If on enzyme replacement therapy, they will be asked to miss up to two biweekly infusions. These patients, along with five control patients with non-enhanceable(classic) Fabry disease, will undergo a comprehensive five day evaluation at the NIH Clinical Center that will include a complete physical examination, functional studies of the heart, eye, kidney and sweat function, imaging of the brain and the heart and a number of blood and urine tests, as well as a skin biopsy.