# DNA methyltransferase 3A (DNMT3A)

Source: https://onco.cc/targets/dnmt3a/  
OnCo record `dnmt3a` (Target). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

DNMT3A writes new methyl marks on DNA; it is one of the most commonly mutated genes in acute myeloid leukaemia and is trapped by the hypomethylating drugs azacitidine and decitabine.

## Summary

DNA methyltransferase 3A establishes new (de novo) cytosine methylation. Loss-of-function mutations, most often at R882, are among the commonest events in acute myeloid leukaemia and in age-related clonal haematopoiesis. Azacitidine and decitabine are incorporated into DNA and covalently trap DNA methyltransferases, including DNMT3A, leading to their degradation and to demethylation.

## Fields

- Kind: Target
- Last checked: 2026-09-04
- Symbol: DNMT3A
- Class: enzyme
- Biology: A de novo methyltransferase working with DNMT3L during development and in haematopoietic stem cells; the R882H mutant acts dominantly to reduce methylation.
- Where found: Haematopoietic stem cells; Mutated in a large share of AML and in clonal haematopoiesis

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/DNMT3A
- UniProt Q9Y6K1: DNMT3A: https://www.uniprot.org/uniprotkb/Q9Y6K1/entry
- HGNC:2978 DNMT3A: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:2978
- ChEMBL target CHEMBL1992: https://www.ebi.ac.uk/chembl/explore/target/CHEMBL1992

## Connected records

- targets: [DNMT1 (DNA methyltransferase 1)](https://onco.cc/targets/dnmt1/)
- cancers: [Acute myeloid leukaemia](https://onco.cc/cancers/aml/), [Myelodysplastic syndromes / neoplasms (MDS)](https://onco.cc/cancers/mds/)
- drugs: [Azacitidine](https://onco.cc/drugs/azacitidine/), [Decitabine](https://onco.cc/drugs/decitabine/)

---
JSON: https://onco.cc/api/v1/entities/dnmt3a.json