title: Usefulness of 4-methylumbelliferyl-6-sulfo-2-acetamido-2-deoxy-beta-D-glucopyrano sid e for the diagnosis of GM2 gangliosidoses in leukocytes.
abstract: 4-Methylumbelliferyl-6-sulfo-2-acetamido-2-deoxy-beta-D-glucopyranoside was synthesized and tested as a substrate for the diagnosis of GM2 gangliosidoses using leukocytes. Less than 2% of normal activity was measured in homogenates from patients with typical Tay-Sachs disease and from a patient with a variant form having 37% Hexosaminidase A by heat denaturation using the usual fluorogenic substrate. An adult patient had 8.5% of normal activity. Three patients with Sandhoff disease were found to have values ranging from 17% to 37% of normal. These values overlap the range found for carriers of Tay-Sachs disease, and suggest that the usefulness of this substrate, while excellent for diagnosing B variants of GM2 gangliosidosis, requires further study. Perhaps when used together with 4-methylumbelliferyl-2-acetamido-2-deoxy-beta-D-glucopyranoside excellent discriminations of patients, carriers and controls will be realized.
mesh_terms: D000118:Acetylglucosaminidase / Q000097:blood*; D005260:Female; D006580:Genetic Carrier Screening; D054818:Hexosaminidase A; D006596:Hexosaminidases / Q000097:blood*; D006801:Humans; D006923:Hymecromone / Q000031:analogs & derivatives; D007962:Leukocytes / Q000201:enzymology*; D008297:Male; D012497:Sandhoff Disease / Q000097:blood / Q000175:diagnosis*; D013379:Substrate Specificity; D013661:Tay-Sachs Disease / Q000097:blood / Q000175:diagnosis*; D014468:Umbelliferones; D001619:beta-N-Acetylhexosaminidases
chemical_list: D014468:Umbelliferones; D006923:Hymecromone; C043647:4-methylumbelliferyl-6-sulfo-2-acetamido-2-deoxy-beta-glucopyranoside; D006596:Hexosaminidases; D000118:Acetylglucosaminidase; D054818:Hexosaminidase A; D001619:beta-N-Acetylhexosaminidases