Mutation analyses in 17 patients with deficiency in acid β-galactosidase: three novel point mutations and high correlation of mutation W273L with Morquio disease type B

An inherited deficiency in beta-galactosidase can result in GM1 gangliosidosis, with several phenotypes of generalized or chronic psychomotor deterioration, as well as in Morquio disease type B, a characteristic mucopolysaccharidosis free of neurological symptoms. We performed mutation analyses in 17 juvenile and adult patients from various European regions with a deficiency in beta-galactosidase and skeletal abnormalities. Fifteen of these had the Morquio B phenotype and have remained neurologically healthy until now while the two others exhibited psychomotor retardation of juvenile onset. A two-base substitution (851-852TG--CT; W273L) was present in 14 of the 15 Morquio B cases. Even if o…