DNMT3A R882 mutations in patients with cytogenetically normal acute myeloid leukemia and myelodysplastic syndrome

Several molecular markers have been described that help to classify patients with acute myeloid leukemia (AML), a heterogeneous hematopoietic tissue neoplasm, into risk groups. We determined the frequency of DNMT3A mutations, their associations with clinical and molecular characteristics and outcome, in primary, cytogenetically-normal AML (CN-AML) and CN-myelodysplastic syndrome (MDS). A total of 63 CN-AML and 16 CN-MDS patients were analyzed for mutations in DNMT3A, codon R822 by direct sequencing and mutation of NPM1 and FLT3/ITD. DNMT3A mutations were found in 17/63 (27%) of CN-AML and in 1/16 (6.3%) of CN-MDS patients. Patients with DNMT3A mutations were older (p=0.047), had higher white blood cell (WBC) counts (p=0.046), more often belonged to FAB groups M4 and M5 (p=0.017), and were more associated with NPM1 mutations (p=0.017), than those with wild-type DNMT3A. DNMT3A-mutated patients had shorter overall disease survival (p<0.001) and disease-free survival (p=0.014) when the entire patient cohort was considered, which remained significant in multivariate analysis. We conclude that DNMT3A R882 mutations are recurrent molecular aberrations in CN-AML, less frequent in CN-MDS, and that testing for R882 mutations may provide a useful tool for refining risk classification of CN-AML.