Stem cell or bone marrow donor who is a relative (usually a brother or sister) of the thalassemic patient. In this case there is a higher probability of HLA -compatibility.
Efforts at reducing the rejection rate by modifying the conditioning regimen should be concentrated on younger patients who have received a small number of transfusions. Patients with thalassemia who have HLA-identical family members should be transplanted before they are in class 3.