title: [Juvenile GM2 gangliosidosis with progressive spinal muscular atrophy onset].
abstract: GM2 gangliosidosis are caused by a beta-hexosaminidase A enzyme deficiency. Mutations in the gene leaving residual enzyme activity give rise to juvenile and adult forms of the disease which have a great clinical heterogeneity. We report three cases which have been considered for some time as Kugelberg-Welander disease. beta-hexosaminidase A was determined with the sulfated synthetic substrate, 4-méthylumbelliferyl-N-acetylglucosamine 6-sulfate (4-MUGS), which allowed the diagnosis. Two of these cases from one family had normal values of hexosaminidase A in serum as found in the B1 variant. Compound mutations were detected. The B1 variants had a classical B1 mutation (G533-->A) and a new mutation located on exon 11. The patient of the second family had the classical mutation of adult GM2 gangliosidosis (Gly269-->Ser) and a new mutation on exon 1, at the initiation codon.
authors.affiliation: Service de Neurologie, CHU Bicêtre, Le Kremlin-Bicêtre.
authors.forename: P
authors.initials: P
authors.lastname: Rondot
authors.forename: R
authors.initials: R
authors.lastname: Navon
authors.forename: B
authors.initials: B
authors.lastname: Eymard
authors.forename: M
authors.initials: M
authors.lastname: Fardeau
authors.forename: J C
authors.initials: JC
authors.lastname: Turpin
authors.forename: M
authors.initials: M
authors.lastname: Lefevre
authors.forename: N
authors.initials: N
authors.lastname: Bathien
authors.forename: Y
authors.initials: Y
authors.lastname: Wu
authors.forename: N
authors.initials: N
authors.lastname: Baumann
mesh_terms: D000328:Adult; D005260:Female; D014644:Genetic Variation; D006579:Heterozygote; D054818:Hexosaminidase A; D006801:Humans; D008297:Male; D009134:Muscular Atrophy, Spinal / Q000209:etiology*; D009154:Mutation; D012497:Sandhoff Disease / Q000175:diagnosis* / Q000201:enzymology / Q000235:genetics; D001619:beta-N-Acetylhexosaminidases / Q000032:analysis / Q000235:genetics
chemical_list: D054818:Hexosaminidase A; D001619:beta-N-Acetylhexosaminidases