[A 32-year old male patient with pathological humeral fracture, splenomegaly and thrombocytopenia].

We describe the case of a 32-year old male patient who presented with a pathological fracture of his right humerus, splenomegaly and thrombocytopenia, the typical symptoms of Gaucher's disease, a lysosomal storage disease. Diagnosis was confirmed by bone marrow biopsy (detection of lipid engorged macrophages - Gaucher cells), by a markedly diminished activity of acid, beta-Glucosidase and by showing two different mutations (764T/A, 1187G/A) in the gene encoding acid beta-Glucosidase. The first mutation causes an amino-acid substitution (phenylalanine to tyrosine). The second mutation causes a premature termination at amino-acid position 396. Enzyme replacement therapy was started with 60 Units/kg body weight, because of severe bone symptoms. Following the decrease in spleen size and increase in platelet count the dose was gradually tapered to 20 U/kg. After two years of enzyme replacement therapy platelet count and spleen volume have normalized and the bone lesions have almost disappeared.