title: Normal serum beta-galactosidase in juvenile GM1 gangliosidosis.
abstract: GM1 gangliosidosis is a genetic disease with lysosomal beta-galactosidase deficiency caused by mutations of the gene coding for this enzyme. However, apparently normal enzyme activity was found in plasma or serum from juvenile GM1 gangliosidosis patients homozygous for a mutation, R201C (201Arg-->Cys), after clotting for 30 min. This extracellular fluid finding is unusual in patients with primary and genetic deficiency of beta-galactosidase. The serum enzyme activity became relatively low only after 3 1/2-hour clotting because its increase in normal controls was not observed in these patients. beta-Galactosidase assay is not always reliable, particularly with serum or plasma as an enzyme source, for the diagnosis of hereditary beta-galactosidase deficiency, unless it is conducted under well-controlled conditions.
authors.affiliation: Department of Clinical Genetics, Tokyo Metropolitan Institute of Medical Science, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Ishii
authors.forename: A
authors.initials: A
authors.lastname: Oshima
authors.forename: H
authors.initials: H
authors.lastname: Sakuraba
authors.forename: Y
authors.initials: Y
authors.lastname: Fukuyama
authors.forename: Y
authors.initials: Y
authors.lastname: Suzuki
mesh_terms: D000293:Adolescent; D000328:Adult; D001483:Base Sequence; D001777:Blood Coagulation; D002648:Child; D002675:Child, Preschool; D005260:Female; D016537:Gangliosidosis, GM1 / Q000201:enzymology* / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009154:Mutation; D001616:beta-Galactosidase / Q000097:blood* / Q000172:deficiency / Q000235:genetics
chemical_list: D001616:beta-Galactosidase