Gene therapy is a new medical method that uses a person’s own genetic material (DNA) to treat diseases. In this study, researchers are using gene therapy to help people with severe blood diseases like sickle cell disease (SCD) and β-thalassemia. They focus on a specific gene called BCL11A to increase healthy fetal hemoglobin (HbF) and lower sickle hemoglobin in the blood. The process is similar to a bone marrow transplant, but instead of using donor cells, the patient's own blood stem cells are modified and given back. This helps avoid risks like Graft-Versus-Host Disease (GVHD), where the donor's cells attack the patient's body. Participants will have their blood stem cells collected and modified, then receive them back through infusion. They will be monitored for 24 months after the procedure.

• Participation includes multiple visits and follow-ups over 24 months.
• No need for a donor; your own cells are used and modified.
• Potential risks include the use of chemotherapy and long-term monitoring.