HSCT For Patients With High Risk Hemoglobinopathies Using Reduced Intensity

Inclusion Criteria: * Patient Inclusion Criteria for Sickle Cell Disease * Patients at least one year of age to less than or equal to 21 years of age with (Sickle Cell Disease-SS or Sickle Cell-S-β-Thalassemia and with one or more of the following disease complications: * Development of stroke on chronic transfusion protocol. * Allosensitization on chronic transfusion therapy * Impaired neuropsychological function and abnormal MRI scan * Abnormal Transcranial Doppler studies * Acute chest syndrome (2 to 3 episodes of acute chest syndrome in last 3 to 4 years). * Ferritin level \< 1500 mg/ml * Recurrent painful priapism; 3-4 episodes/year requiring intervention. * Recurrent vaso-occlusive crisis of at least 3 to 4 episodes/year. * Osteonecrosis of multiple bones with documented destructive changes. * Signed informed consent * Patients physically and psychologically capable of undergoing transplantation and a period of strict isolation. * Ferritin \< 1500 * Liver Iron Concentration \< 6mg/g Patient Inclusion Criteria for β Thalassemia major Patients less than or equal to 21 years of age with B- Thalassemia major on routine monthly transfusion protocol or with one or more of the following complications; 1. Hepatomegaly. 2. Liver biopsy revealing evidence of portal fibrosis as A) Mild B) Moderate 3. Ferritin level≤ 1500ng/ml 4. Liver Iron Concentration (LIC) \< 6mg/g Exclusion Criteria: * Exclusion Criteria for Both Sickle Cell and β Thalassemia Major Patient * HIV positive result confirmed by Western Blot. * Pregnancy (Pregnancy testing for females of child-bearing age will be performed and those with a positive serum β-Human Chorionic Gonadotropin will be excluded) and lactating females. * Creatinine greater than two times the upper limit of normal for the laboratory, * Pulmonary disease with FVC, FEV1 or DLCO parameters \< 50% predicted (corrected for hemoglobin) or stage 3 or 4 sickle lung disease. * Cardiac insufficiency or coronary artery disease requiring treatment * Active infection requiring systemic antibiotic therapy with antibacterial, antifungal or antiviral agents * Lansky performance score \<70%- (Appendix B) * Acute hepatitis/biopsy evidence of cirrhosis. * Pulmonary Hypertension