A hemizygous bone marrow transplant is one in which only one HLA chromosome is present in the donor-recipient match for the bone marrow transplant. With a hemi-matched bone marrow transplant, most patients will be able to find a donor, which can be a parent, sibling, etc. The majority of patients will be able to find a donor for a bone marrow transplant. When the patient is in remission and a fully matched donor is not available, hemizygous bone marrow transplantation is an option. Hemi-compatible bone marrow transplantation requires more attention to the occurrence of graft rejection and close monitoring after treatment, with prompt treatment of any abnormalities.