Patients with frequent and severe complications in early childhood are typically felt to be at highest risk for continued debilitating problems and early death. These severely affected children have been the subject of efforts to cure SCD through bone marrow transplantation (BMT) from a healthy donor. BMT is curative for SCD because it provides a source of normal hemoglobin production. BMT is performed by giving the patient high doses of chemotherapy, then infusing bone marrow from a healthy donor into a large vein in the recipient, followed by an intensive period of supportive care and immune suppression. Over 200 patients with SCD have been transplanted world-wide, primarily from sibling donors who are HLA (tissue or transplantation type) matched. Of those transplanted in a North American cooperative study, about 95% of these patients survived the transplant, and about 85% are free of sickle cell disease. The Atlanta program was the largest contributor to this study. Through 2004, Atlanta has transplanted 18 children with SCD from matched siblings; all are free of sickle cell disease and none have died.