title: The change in the pH 4 and pH 6 forms of alpha-glucosidase in cultured amniotic fluid cells and its implication in prenatal diagnosis of Pompe's disease.
abstract: Activities of two major forms of alpha-glucosidase in cultured amniotic fluid cells have been measured by the 4-methylumbelliferyl-alpha-D-glucoside assay after 3, 6 and 9 weeks of culturing. Activity of the pH 4 forms of alpha-glucosidase, which is deficient in Pompe's disease, was low in early culture but increased rapidly as the culture time was increased. The cells harvested at 3 weeks had a low absolute activity of the pH 4 form as well as low ratio of the pH 4 to pH 6 enzyme. The pH 6 form is not affected in Pompe's disease. The results suggest cautions when attempting early diagnosis by use of microtechniques and re-emphasizes the need for differentiation of these two forms of alpha-glucosidases in prenatal diagnosis of Pompe's disease.
mesh_terms: D000653:Amniotic Fluid / Q000201:enzymology*; D002478:Cells, Cultured; D005260:Female; D005959:Glucosidases / Q000378:metabolism*; D006008:Glycogen Storage Disease / Q000175:diagnosis*; D006009:Glycogen Storage Disease Type II / Q000175:diagnosis* / Q000201:enzymology; D006358:Hot Temperature; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D011247:Pregnancy; D011296:Prenatal Diagnosis; D000520:alpha-Glucosidases / Q000378:metabolism*
chemical_list: D005959:Glucosidases; D000520:alpha-Glucosidases