GENERAL CHARACTERISTICS: Gaucher's disease is a genetic disease of autosomal recessive transmission due to a deficit in a lysosomal enzyme: beta-glucocerebrosidase. The disease is characterised by deposits of glucosylceramide in the cells of the liver, spleen and bone marrow. Acute or chronic neurological forms (type 2 and 3) account for only 5% of patients suffering from Gaucher's disease and are less frequent than the non-neurological forms (type 1). CLINICAL AND BIOCHEMICAL MANIFESTATIONS: Gaucher's disease is associated with spleno- or hepato-megalia, asthenia, bone complications (Erlenmeyer flask deformity, osteopenia and osteonecrosis), as well as with haematological (thrombopenia, anaemia) or biochemical abnormalities (increase in angiotensin-converting enzyme, ferritin, tartrate-resistant acid phosphatase and chitotriosidase). Central nervous system involvement is only found in the type 2 and 3. Diagnosis relies on measurement of beta-glucocerebrosidase activity in the circulating leukocytes. REGARDING TREATMENT: Treatment with enzyme replacement (imiglucerase: recombinant enzyme preparation) improves the haematological abnormalities, hepatosplenomegalia and quality of life in a matter of a few months. Regression of the bone disorders is usually observed only after 3-4 years of treatment. Recently, gene therapy trials have successfully been started.