Bone marrow dysfunction manifested by one or more cytopenia(s) (ANC < 1.0 × 109/L, Hb < 10 g/dL, or platelets < 100 × 109/L), but no obvious non-mast cell hematopoietic malignancy.Palpable hepatomegaly with impairment of liver function, ascites, and/or portal hypertension.Skeletal involvement with large osteolytic lesions and/or pathological fractures.Palpable splenomegaly with hypersplenism.Malabsorption with weight loss due to gastrointestinal mast cell infiltrates. This evidence concerns the gene GSTM1 and Splenomegaly.