Monosomy 7 in donor cell-derived leukemia after bone marrow transplantation for severe aplastic anemia: report of a new case and review of the literature

monosomy 7 arises as a recurrent chromosome aberration in donor cell leukemia after hematopoietic stem cell transplantation. we report a new case of donor cell leukemia with monosomy 7 following hla-identical allogenic bone marrow transplantation for severe aplastic anemia (saa). the male patient received a bone marrow graft from his sister, and monosomy 7 was detected only in the xx donor cells, 34 months after transplantation. the patient's bone marrow microenvironment may have played a role in the leukemic transformation of the donor hematopoietic cells.