Trisomy 4 in 'stem cell-like' leukemic cells of a patient with AML.

CD34 positive progenitor cells were analyzed in the bone marrow aspirate from a patient with newly diagnosed AML FAB M4. The patient had trisomy 4 as sole cytogenetic abnormality and a dominant population of CD34 negative leukemic blasts. Karyotyping of the FACS isolated, minor subpopulation of CD34+/CD38-, 'stem cell'-like cells (incidence 0.29%) revealed trisomy 4 in 11/13 metaphases. No metaphases were obtained in the CD34 negative subpopulation. The experiments point to the existence of leukemic stem cells in the CD34+/CD38- compartment in AML patients with trisomy 4.