A review.Enzyme replacement therapies substitute particular enzymes in individuals who have deficient or absent levels of enzymic activity due to inherited defects.Fabry disease, a rare X-linked genetic disorder yet common lysosomal storage disease, is due to the impaired activity of α-galactosidase A.Currently, there are two enzyme preparations available for the treatment of Fabru disease: agalsidase alfa (Replagal), manufactured by Shire, and agalsidase beta (Fabrazyme), manufactured by Genzyme.Here, we review the mol. characteristics and intracellular trafficking of the endogenous and exogenous enzymes as well as the pharmacol. properties of Replagal.We also summarize clin. experiences with Replagal and provide insight into its therapeutic value for the treatment of Fabry disease.