Multi-Center Study of Iron Overload: Survey Study (MCSIO)

Inclusion Criteria: * 10-20 years of transfusion (defined as 0.2-0.6mg Fe/kg/day exposure with annual ferritin levels greater than 2500 in at least 60% of years of chronic transfusion); * 0 to 9 years old at the initiation of chronic transfusions; no exchange transfusions in the previous 6 months * iron overload documented by either liver biopsy, MRI or SQUID with estimated LIC of greater than 7 mg/g dry wt in the previous 6 months or ferritin level greater than 1500mg/dl. Exclusion Criteria: * Patients with HbSC, HbS/β thalassemia * Pacemaker (active or inactive) or other implanted magnetic devices, severe claustrophobia, or other contraindications to MRI; Unable to remove ferro-magnetic objects from the body in regions to be imaged (e.g., jewelry or piercing) * Presence of any other condition which, in the opinion of the investigator, would make the patient unsuitable for enrollment; * Any chronic inflammatory illness other than the SCD, THAL or DBA; * Any acute illness within a 14 day period prior to blood sampling; * Patients receiving intensive chelation in the 6 months prior to enrollment including deferoxamine 24 hours per day, 7 days per week or combination treatment with 2 chelators * Pregnancy