title: Sialidosis: delineation of subtypes by neuraminidase assay.
abstract: A sensitive assay for acid neuraminidase using 4-methylumbelliferyl-alpha-D-N-acetylneuraminic acid is described. In skin fibroblasts, patients with sialidosis Types 1 and 2 have severe deficiencies of neuraminidase activity compared with controls. Patients with Type 1 sialidosis have activities which are 10 times higher than those with Type 2 sialidosis, in keeping with their milder clinical involvement. Two Italian patients with Type I sialidosis had a Km which was one-sixth normal; the other patients had a Km in the normal range.
mesh_terms: D002478:Cells, Cultured; D005347:Fibroblasts / Q000201:enzymology; D006801:Humans; D006923:Hymecromone / Q000031:analogs & derivatives; D009081:Mucolipidoses / Q000145:classification / Q000201:enzymology*; D009439:Neuraminidase / Q000378:metabolism*; D012867:Skin / Q000201:enzymology
chemical_list: D006923:Hymecromone; C021224:2'-(4-methylumbelliferyl)-alpha-D-N-acetylneuraminic acid; D009439:Neuraminidase