Clinical importance of cytogenetics in acute myeloid leukaemia

Acquired chromosome aberrations are present in the marrow of most patients with acute myeloid leukaemia (AML) at diagnosis. Cytogenetically, AML is a very heterogeneous disease with over 160 structural chromosome abnormalitie s observed recurrently to date. Molecular dissection of many reciprocal tra nslocations and inversions has resulted in cloning of the genes involved in leukaemogenesis. Some recurrent aberrations and the resulting gene rearran gements, namely inv( 16)/t( 16;16) and CBF beta -MYHII, t(8;21) and CBF2-CB F2TI, t(15; 17) and PML-RAR alpha, and rearrangements of band 11q23 and the MLL gene, are now used to help define distinct disease entities within AML in the new World Health Organization classification of haematological mali gnancies, Moreover, cytogenetic abnormalities, whether molecularly characte rized or not, are among the most important, independent prognostic factors in AML, and are being used in the management of AML patients. This review p resents current information on chromosome abnormalities in AML, and on asso ciations between karyotype and clinical characteristics and outcome of AML patients.