Urinary alpha-glucosidase analysis for the detection of the adult form of Pompe's disease.

Two alpha-glucosidases from human heart, liver, muscle, kidney and urine have been separated by means of Sephadex G-100 gel filtration. The first peak (Peak I) was neutral alpha-glucosidase and the second peak (Peak II) was lysosomal acid alpha-glucosidase. Peak II was absent in a patient with the adult form of Pompe's disease. KCl stimulated the activity of the Peak II enzyme but it strongly inhibited the activity of the Peak I enzyme measured at pH 4.0. Decreases in the urinary alpha-glucosidase activity measured at pH 4.0 with added KCl and the ratio of the activity at pH 4.0 with added KCl/the activity at pH 6.5 without KCl may aid in the detection of homozygotes or heterozygotes with the adult form of Pompe's disease.