This study investigates the safety and effectiveness of a new type of transplant for people with Severe Sickle Cell Disease (SCD). The transplant is called a haploidentical transplant, which means it comes from a donor who is a half match genetically, like a parent or sibling. The purpose is to determine if this type of transplant can be a treatment option for SCD.

Participants in the study will undergo a procedure where they receive bone marrow from a related donor who is a half match. The study involves monitoring the participants for any side effects and measuring the success of the transplant in treating SCD. A haploidentical transplant involves using bone marrow from a donor who shares some, but not all, of the genetic markers with the recipient.

• Who can participate: Participants must have sickle cell anemia and a first-degree relative willing to donate bone marrow. They must not have an HLA-matched sibling donor, uncontrolled infections, or HIV.
• Study details: Participants will receive a bone marrow transplant from a half-matched relative. This involves a medical procedure followed by monitoring to assess the transplant's effectiveness and safety. No placebo is used in this study.