Mutations of the transcription factor CEBPA (CCAAT/enhancer binding protein alpha) have been reported in approximately 15% of patients with acute myeloid leukemia (AML) with a normal karyotype. CEBPA plays a role in the differentiation of granulocytes. Two types of mutations have been reported: N-terminal changes which result in a truncated dominant negative isoform lacking one of the N terminal domain transactivation domains and C-terminal mutations which are in-frame insertions or deletions affecting the leucine zipper and preventing dimerization and DNA binding. Patients may carry both N- and C-terminal mutations affecting different alleles. Isolated, biallelic ("double") mutations (not single mutation) of CEBPA appear to be associated with a favorable-risk group of normal karyotype AML. CEBPA mutations have also been reported in association with hereditary myeloid disorders; 5-10% of CEBPA double mutant AML cases may harbor germline mutations. Recommend correlation with clinical findings including family history and genetic counseling, if there is clinical suspicion of an inherited disorder.