Immunoquantification of -Galactosidase: Evaluation for the Diagnosis of Fabry Disease

of glycosphingolipid catabolism resulting from a defi-ciency of the lysosomal exoglycohydrolase, -galactosi-dase. Enzyme replacement therapy is currently available for Fabry disease, but early diagnosis before the onset of irreversible pathology will be mandatory for successful treatment. Presymptomatic detection would be possible through the use of a newborn-screening program. We report on the use of sensitive assays for the measure-ment of -galactosidase protein and activity and for the protein saposin C, which are diagnostic markers for Fabry disease. Methods: Two sensitive immunoassays for the measure-ment of -galactosidase activity and protein were used to determine the concentrations of -galactosidase in dried filter-paper blood spots and plasma samples fro