Pre-transplant Immunosuppression and Donor Stem Cell Transplant for the Treatment of Severe Hemoglobinopathies

This clinical trial studies the effect of pre-transplant immunosuppression (PTIS) and donor stem cell transplant in treating patients with severe blood diseases (hemoglobinopathies). PTIS helps prepare the body for the transplant and lowers the risk of developing graft versus host disease (GVHD). Hematopoietic cells are found in the bone marrow and produce blood cells. Hematopoietic cell transplantation (HCT) injects healthy hematopoietic cells into the body to support blood cell production. PTIS and HCT may help to control severe hemoglobinopathies.