A patient is described with de novo acute non-lymphocytic leukemia of megakaryoblastic lineage with tri-lineage myelodysplasia. This patient was studied cytogenetically and using molecular genetic techniques throughout her clinical course. She had an N-ras mutation at diagnosis which persisted despite a bone marrow transplant, and acquired a Philadelphia chromosome associated with a P190 BCR-ABL transcript at clinical relapse 3 months post-transplantatio
