Inclusion:

• Patients with homozygous B0/+ thalassemia or severe variants of B0/+ thalassemia with an HLA genotypically identical donor.
• Patients with an HLA genotype identical donor and hemoglobin SS, hemoglobin SC, or hemoglobin Sb 0/+ and at least one of the following:

Previous central nervous system vaso-occlusive episode with or without residual neurologic findings; Frequent painful vaso-occlusive episodes which significantly interfere with normal life activities and which necessitate chronic transfusion therapy; Recurrent SCD chest syndrome events which necessitate chronic transfusion therapy.

• Severe anemia which prevents acceptable quality of life and necessitates chronic transfusion therapy.
• The patient must have an HLA genotype identical donor.
• Between the ages of birth and 65 years.
• Women of childbearing potential must have a negative pregnancy test.

Exclusion:

• Biopsy proven chronic active hepatitis or fibrosis with portal bridging.
• SCD chronic lung disease >/= stage 3.
• Severe renal dysfunction defined as creatinine clearance <40 ml/min/1.73 M2
• Severe cardiac dysfunction defined as shortening fraction <25%.
• HIV infection.
• Severe but unspecified chronic toxicity serious enough to detrimentally affect the patient's capacity to tolerate bone marrow transplant (BMT).
• Inadequate intellectual capacity to understand the nature and risk inherent in the BMT process and give informed consent (in the case of minors, this criteria must be fulfilled by the legal guardian).
• Pregnant, lactating or unwilling to use appropriate birth control.