The purpose of this study is to initiate pilot studies to demonstrate that a sufficient number of iron-overloaded thalassemia, SCD and DBA populations with similar duration of chronic transfusion, and age at start of transfusions would be available for a confirmatory study and to validate that proposed multicenter MRI and biochemical studies can be completed. The study will examine the hypothesis that a chronic inflammatory state in Sickle Cell Disease (SCD) leads to hepcidin- and cytokine-mediated iron withholding within the RES (reticuloendothelial system), lower plasma NTBI (non transferrin bound iron) levels, less distribution of iron to the heart in SCD.