β ‐Glucosidase activities in the Norrbotten type of juvenile Gaucher's disease

β-Glucosidase and N-acetyl-β-glucosaminidase activities were measured with synthetic substrates in peripheral leucocytes, urine and serum from patients with juvenile type of Gaucher's disease. Our findings in urine and serum make it clear that diagnosis by using synthetic substrate is not possible. In peripheral leucocytes reduced level was found for β-glucosidase activity in patients with Gaucher's disease but also there occurred some overlapping with controls. The possible explanation to these findings are discussed.