Subject is a male hemizygote, age 18 years or older, with confirmed diagnosis of Fabry Disease. Diagnosis of Fabry disease may be confirmed by proof of a mutation of the alpha-Galactosidase A gene compatible with Fabry Disease and/or a deficiency of alpha-Galactosidase A (less than 4.0 nmol/mL/hour in plasma or serum or less than 8% of average mean normal in leukocytes).