MORQUIO SYNDROME (MUCOPOLYSACCHARIDOSIS-IV-B) ASSOCIATED WITH BETA-GALACTOSIDASE DEFICIENCY - REPORT OF 2 CASES

  • 1 January 1980
    • journal article
    • research article
    • Vol. 32  (2) , 258-272
Abstract
Two male patients, aged 6 and 25 yr, both with normal intelligence and absence of neurological abnormalities, exhibited dysostosis multiplex, dwarfism, odontoid anomalies, cloudy corneas, excessive excretion of keratan sulfate and abnormal urinary oligosaccharides. Leukocytes and fibroblasts of both patients were deficient in acid .beta.-galactosidase (.beta.-gal) and normal in N-acetylgalactosamine-6-sulfate sulfatase, the deficient enzyme in classical Morquio syndrome. The .beta.-gal deficiency was not due to an endogenous inhibitor, and the parents exhibited intermediate activities. Deficient .beta.-gal activity was observed toward p-nitrophenyl-.beta.-galactoside, 4-methylumbelliferyl-.beta.-galactoside (4 MU-.beta.-gal), lactose, GM1 ganglioside, keratan sulfate and asialofetuin (ASF). Under standard assay conditions, the residual activity was similar for all substrates tested. Toward p-nitrophenyl-.beta.-galactoside, the mutant enzyme behaved as a Km variant.