GSTM1 and Thrombocytopenia: After ERT all patients showed decrease in the size of their spleen and liver after 3, 6 12 months of ERT, which mean a good response to the enzyme, and on the other hand, Hb level reached normal level in 67% of anemic patients after 6 months of treatment and the platelet count reached normal in 53.8% of the patients who presented with thrombocytopenia before treatment.