Morquio B syndrome: a primary defect in beta-galactosidase.
Am J Med Genet
; 16(2): 261-75, 1983 Oct.
Article
em En
| MEDLINE
| ID: mdl-6418007
ABSTRACT
Fibroblasts from patients with Morquio B syndrome contain normal numbers of beta-galactosidase molecules with normal turnover but strongly reduced activity per enzyme molecule. Various substrate affinities are abnormal the Km for methylum belliferyl (MU)-beta-galactoside is 4-10-fold elevated and affinity for keratan sulphate and oligosaccharides, isolated from Morquio B urine, was not detectable. In contrast, these substrate affinities are normal for beta-galactosidase in adult type GM1-gangliosidosis fibroblasts. Cell hybridization studies demonstrate that Morquio B syndrome and infantile and adult type GM1-gangliosidosis belong to the same complementation group. From these results we conclude that Morquio B syndrome is caused by a mutation in the structural gene for beta-galactosidase, which is allelic to the mutations in infantile and adult type GM1-gangliosidosis. Urinary excretion of keratan sulphate and oligosaccharides is abnormal in Morquio B syndrome but normal in adult type GM1-gangliosidosis. The catalytic properties of beta-galactosidase in Morquio B syndrome and GM1-gangliosidosis provide a possible explanation for the distinct clinical manifestations in these disorders.
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Base de dados:
MEDLINE
Assunto principal:
Beta-Galactosidase
/
Mucopolissacaridose IV
/
Galactosidases
Limite:
Humans
Idioma:
En
Ano de publicação:
1983
Tipo de documento:
Article