DNMT3A (R882) mutation features and prognostic effect in acute myeloid leukemia in Coexistent with NPM1 and FLT3 mutations

Abstract

Objective/background: In the absence of high-risk cytogenetic, DNMT3A (DNA Methyltransferase 3a) mutation status has an impact on outcome in the presence of FLT3 (FMS-like Tyrosine Kinase3) and/or NPM1 (Nucleophosmin). In this study, we focus on the features and effect of DNMT3A (R882) mutation in acute myeloid leukemia (AML) in the presence or absence of NPM1 and FLT3 mutations.

Methods: A total of 174 cytogenetically normal (CN)-AML cases were analyzed for NPM1, FLT3, and DNMT3A mutations. For NPM1 mutation detection, we used the pyrosequencing technique; for FLT3 mutations, polymerase chain reaction and RFLP with ECO-RV techniques were used, and for DNMT3A mutation analysis, we used Sanger sequencing and RFLP (Restriction Fragment Length Polymorphism) techniques.

Results: NPM1 mutation was found in 40.80%, DNMT3A in 12.06%, and FLT3 mutation was found in 16.66% of 174 CN-AML patients. We also found seven cases which were (NPM1+, FLT3+), 10 cases which were (NPM1+, DNMT3A+), and two cases were found positive for (DNMT3A+, FLT3+) mutations. Adult patients had significantly higher frequency of NPM1 mutation than children (72.22% vs. 16.66%; p = .020), whereas FLT3/ITD and DNMT3A mutation was associated with higher white blood count (p = .081). Immunophenotypically, NPM1 and DNMT3A mutations were significantly associated with the lack of CD34, whereas FLT3/ITD mutation was positively associated with the expression of CD7. We also assessed the overall survival and progression-free survival of DNMT3A mutation status among patients with CN-AML. Indeed, DNMT3A mutations within the CN-AML subset were associated with significantly shorter overall survival and progression-free survival compared to NPM1 and FLT3 mutated patients (p = .067 and p = .065, respectively).

Conclusion: DNMT3A R882 mutation plays an important role in CN-AML patients' prognosis and clinical outcomes in the presence and absence of NPM1 and FLT3 mutations.

Keywords: CN-AML; DNMT3A; FLT3; NPM1.