K313dup is a recurrent CEBPA mutation in de novo acute myeloid leukemia (AML).

The CEBPA gene codes for a transcription factor that has a pivotal role in controlling proliferation and differentiation of myeloid progenitors. Acquired CEBPA mutations have been found in acute myeloid leukemias (AML) with a good prognosis, and most of these patients have a normal karyotype. In this paper, we report four cases that displayed the same K313dup in the CEBPA gene. All four had an AML-M1 with CD7 positivity and T-cell receptor gamma chain (TCR-gamma) rearrangement. This mutation could represent nearly 10% of all CEBPA mutations described to date. K313dup disappeared in samples from patients in complete remission. In transfected cells, the K313dup mutant had reduced protein stability with respect to the wild-type protein. K313dup seems to be selected in leukemic cells, and its frequency in other AML series could be determined using the screening method reported in this paper.