Dynamics of DNMT3A mutation and prognostic relevance in patients with primary myelodysplastic syndrome

Background: DNMT3A gene mutation has been associated with poor prognosis in acute myeloid leukemia, but its clinical implications in myelodysplastic syndrome (MDS) and dynamic changes during disease progression remain controversial. Results: In this study, DNMT3A mutation was identified in 7.9% of 469 de novo MDS patients. DNMT3A-mutated patients had higher platelet counts at diagnosis, and patients with ring sideroblasts had the highest incidence of DNMT3A mutations, whereas those with multilineage dysplasia had the lowest incidence. Thirty-one (83.8%) of 37 DNMT3A-mutated patients had additional molecular abnormalities at diagnosis, and DNMT3A mutation was highly associated with mutations of IDH2 and SF3B1. Patients with DNMT3A mutations had a higher risk of leukemia transformation and shorter overall survival. Further, DNMT3A mutation was an independent poor prognostic factor irrespective of age, IPSS-R, and genetic alterations. The sequential study demonstrated that the original DNMT3A mutations were retained during follow-ups unless allogeneic hematopoietic stem cell transplantation was performed, while DNMT3A mutation was rarely acquired during disease progression. Conclusions: DNMT3A mutation predicts unfavorable outcomes in MDS and was stable during disease evolutions. It may thus be a potential biomarker to predict prognosis and monitor the treatment response.