Why is bone marrow from a genetically matched donor preferred for a transplant in ADA deficiency?

• A. To prevent rejection / immune response
• B. To ensure faster engraftment
• C. To increase ADA enzyme production
• D. To reduce need for hygiene measures

Answer: (A)

Matching the donor genetically reduces immune incompatibilities between the patient and the transplanted marrow. When the recipient’s body sees donor cells as foreign, the immune system can reject the transplant, and donor immune cells can also attack the recipient in graft-versus-host disease. A genetically matched donor minimizes these mismatches, making engraftment of the donor stem cells more likely and lowering the risk of immune complications. In ADA deficiency, the goal is to reconstitute a functional immune system with healthy donor cells, so compatibility is a key factor. The enzyme production will come from the donor-derived cells, but this depends on successful engraftment rather than the level of matching alone. Hygiene measures aren’t directly related to why a matched donor is preferred.