We studied a prospectively assembled consecutive cohort of 585 patients (71% male) from 2 hypertrophic cardiomyopathy tertiary referral centers by screening for low α-galactosidase A activity in dried blood spots.
To test whether reduction in lysosomal enzymatic activity in PD is specific to GCase, we measured GCase, acid sphingomyelinase (deficient in Niemann-Pick disease types A and B), alpha galactosidase A (deficient in Fabry), acid alpha-glucosidase (deficient in Pompe) and galactosylceramidase (deficient in Krabbe) enzymatic activities in dried blood spots of PD patients (n = 648) and controls (n = 317) recruited from Columbia University.
Methods- Participants included Parkinson disease patients and nonblood-related controls, whose GLA and GAA enzymatic activities were measured in dried blood spots.
Dried blood spots on Guthrie papers were used to analyze α-Gal A enzyme and genetic analysis was performed in individuals with enzyme activity ≤1.2 μmol/L/h.
GLA activity in dried blood spots was measured using a fluorescence assay and confirmed by measurement of GLA activity in white blood cells (WBCs) in infants with abnormally low GLA activity.
Recently, male subjects harboring the c.196G>C nucleotide change which leads to the E66Q enzyme having low α-galactosidase A (GLA) activity have been identified at an unexpectedly high frequency on Japanese and Korean screening for Fabry disease involving dry blood spots and plasma/serum samples.
To determine the disease incidence, we undertook newborn screening by assaying the alpha-Gal A activity in blood spots from 37,104 consecutive Italian male neonates.