Three cases of beta-galactosidase deficiency.

A clinical description of three cases of beta-galactosidase deficiency is presented. Two cases are classical for infant type GM1-gangliosidosis, the third is characterised by dysostosis multiplex with growth retardation and of normal intelligence. Laboratory data revealed mucopolysaccharides in the urine of all described patients in a high level of normal values and increased excretion of oligosaccharides in the urine. Both patients with a classical picture of GM1-gangliosidosis have a very low activity of beta-galactosidase, activity of beta-galactosidase in their parents cells is diminished by 50% of control. In the third nontypical case enzyme deficiency was less expressed. These cases emphasize the variability of the clinical expression in beta-galactosidase deficiency.