Genetic abnormalities in core binding factor acute myeloid leukemia.

Acute myeloid leukemia (AML) is a genetically heterogeneous disease, and its prognosis is stratified on the basis of chromosomal and genetic alterations. Core binding factor (CBF) leukemia consists of AML with t (8;21) (p22;q22) and inv16 (q16q16) /t (16;16) (q16;q16) and is included in AML with recurrent genetic abnormality according to WHO classification. Although CBF-AML is categorized as favorable-risk AML, approximately 40% of patients show relapse. The t (8;21) and inv16 (q16q16) /t (16;16) (q16;q16) result in RUNX1-RUNX1T1 and CBFB-MYH11 fusion genes, respectively; however, the fusion proteins encoded by these genes alone are insufficient for the development of leukemia. Activating kinase mutations in KIT, FLT3, and N-RAS have been frequently found, and their cooperation with RUNX1-RUNX1T1 or CBFB-MYH11 is thought to be crucial for leukemogenesis in CBF-AML. Recently, mutations in ASXL2, ZBTB7A, CCND2, and DHX15 have been frequently identified in t (8;21) AML, but their biological and clinical significance have not been elucidated. Thus, a combination of several genetic alterations is associated with the development of CBF-AML, and comprehensive genetic analysis is necessary for the stratification of this leukemia. CBF-AML is a still heterogeneous disease entity, and it is necessary to elucidate the combinations of genomic abnormalities and clonal evolutions for better understanding of the disease and to develop a new treatment strategy.