[NPM1 and CEBPA mutations in pediatric cytogenetically normal acute myeloid leukemia]

To evaluate the frequency of the nucleophosmin (NPM1) gene and the CCAAT/enhancer binding protein α gene (CEBPA) through polymerase chain reaction (PCR) array in pediatric patients with cytogenetically normal acute myeloid leukemia (CN-AML) and explore the clinical significances of these mutations.

Between August 2009 and December 2012, 30 children (<16 years old) with newly diagnosed CN-AML were included. The clinical characteristics were analyzed in these patients. PCR combined with direct sequencing was used to detect NPM1, CEBPA gene mutations. All the data were statistically analyzed using SPSS17.0 software.

The gene mutations were detected in each of the 30 patients. NPM1 mutation was positive in three patients (10%) with type A mutation, while CEBPA mutation was positive in two patients (6.7%) with double mutations (TAD, bZIP) . Besides, FLT3/ITD mutation was positive in three patients. Patients with NPM1 or FLT3/ITD had a significantly elevated diagnostic WBC count with a median diagnostic WBC count of 102.80×10(9)/L compared with 18.56×10(9)/L for the patients without mutations(t = 2.353, P = 0.043), as well as the marrow blast percentage (94.0% vs. 80.0%, t = 3.804, P = 0.002). The complete remission was achieved in all the 3 patients with NPM1 mutations and 2 patients with CEBPA mutations. All the patients with these mutations also achieved 2-year event-free survival (EFS) and 2-year overall survival (OS), while 2-year EFS and 2-year OS of the other patients were (40.1 ± 11.2)% and (51.8 ± 10.9)% (P = 0.044, 0.091, respectively).

NPM1 and CEBPA mutations may indicate a favorable prognosis in pediatric CN-AML.