Alpha thalassemia has clinically 2 significant forms. These are Bart hydrops fotalis hemoglobin (Hb Bart) syndrome and hemoglobin H (HBH) disease. Hb Bart syndrome is the severe formof the disease and charactirezed by edema all over the body during penatal stage, pleural and pericardiyal edema with a severe hypochromic anemia and.

Clinical features are hepatospenomegaly, extramedullary erythropoiesis, hydrocephalus, cardiac and urogenital anomalies. HBH disease shows itself with hepatosplenomegaly and microcytic hypochromic hemolytic anemia symptoms.