Background. Enzyme Replacement Therapy (ERT) is the standard of care in Gaucher disease. The effects of withdrawal or reduced doses are debated, thus a retrospective cohort study was conducted to investigate clinical and laboratory differences in 34 Gaucher type 1 patients experiencing an ERT dosage reduction after the forced temporary imiglucerase shortage in 2009.Methods. Haemoglobin concentration, leukocytes and platelets counts, and chitotriosidase activity were assessed at baseline and after 6 and 12 months (t0, t6, t12), while bone pain, energy, work or school performance, concentration, memory and social life every 3 months.