GENE REFERENCE / HGNC:2978
DNMT3A
DNA methyltransferase 3 alpha
What does this gene do?
The DNMT3A gene provides instructions for making an enzyme called DNA methyltransferase 3 alpha. This enzyme is involved in DNA methylation, which is the addition of methyl groups, consisting of one carbon atom and three hydrogen atoms, to DNA molecules. In particular, the enzyme helps add methyl groups to DNA building blocks (nucleotides) called cytosines.
DNA methylation is important in many cellular functions. These include determining whether the instructions in a particular segment of DNA are carried out or suppressed (gene silencing), regulating reactions involving proteins and fats, and controlling the processing of chemicals that relay signals in the nervous system (neurotransmitters). DNA methyltransferase 3 alpha is particularly important for establishing DNA methylation patterns during development before birth. The enzyme also functions in early cells that can give rise to more mature cell types. In early blood cells, called hematopoietic stem cells, the methylation patterns established by DNA methyltransferase 3 alpha promote maturation (differentiation) into different blood cell types.
Related condition topics
MedlinePlus mentions this gene in the condition pages below. These links alone do not show that the gene causes a condition.
ClinGen reviews
ClinGen reviews the evidence linking a particular gene to a condition. Each rating below describes the strength of that link. It does not classify a variant in your DNA file.
| Condition | Inheritance | Evidence |
|---|---|---|
| Heyn-Sproul-Jackson syndromeMONDO:0032882 · Evaluated 2023-06-07 | Autosomal dominant | LimitedIntellectual Disability and Autism Gene Curation Expert Panel |
| Tatton-Brown-Rahman overgrowth syndromeMONDO:0014382 · Evaluated 2023-06-08 | Autosomal dominant | DefinitiveIntellectual Disability and Autism Gene Curation Expert Panel |
ClinVar records
These numbers show what has been submitted to ClinVar. They cannot tell you how likely you are to have a condition.
- Submitted alleles
- 1,447
- Submissions for variants in or overlapping this gene
- 2,094
- Submissions explicitly reporting this gene
- 2,023
- Alleles reported pathogenic / likely pathogenic
- 240
- VariationIDs with uncertain significance
- 539
- VariationIDs with conflicting classifications
- 36
The rows count different things: alleles, submissions or VariationIDs. Their categories can overlap, so do not add them together. Pathogenic/likely pathogenic counts exclude structural variants that merely overlap a gene. A dash in the source means “not reported,” not zero.
NCBI produces the gene-summary file each week using counts recorded at the start of the month. The numbers may differ from those on the live ClinVar website. Read the field definitions ↗
YOUR DNA FILE
Can your DNA file tell you about DNMT3A?
From a DNA test kit (such as 23andMe, AncestryDNA or MyHeritage). These kits check a fixed list of about 600,000 to 700,000 positions across your whole genome. ClinVar lists 240 alleles in DNMT3A reported as pathogenic or likely pathogenic. A kit checks only some of these positions, and often none of them.
From whole genome sequencing (a VCF file). Sequencing reads most of your genome. Your file lists the places where your DNA differs from the reference genome. Some regions are hard to sequence, including parts of some genes that have near-identical copies elsewhere, and a VCF file does not record which positions were read well.
If a variant is not in your file, that does not mean you don’t have it.
What BioDecode checks
BioDecode compares every variant in your file with ClinVar, on your own computer. For each match, it shows the ClinVar classification, the review status and the condition it was reported for. Your file is not uploaded.
A ClinVar classification applies to one particular variant and the condition it was reported for. It does not tell you about other variants in DNMT3A.
BioDecode cannot fill gaps in your test, diagnose a condition or replace clinical testing.
Sources and dates
The source information on this page last changed on 2026-10-24.
HGNC Source details
Source release: Fri, 16 Oct 2026 13:36:12 GMT
Source record updated: 2023-01-20
SHA-256: 72bfe0c05800163c040a2cf663c70501f9ac9236469fbd0b552f2cd37a4d7f67
MedlinePlus Source details
Source release: Sat, 24 Oct 2026 05:15:45 GMT
Source publication: 2023-04-10
Source review: 2017-09
SHA-256: fdc8bd614310c12718379cef6569962e5d0e791cecabcc355b53a72816ac263a
ClinVar Source details
Source release: Mon, 19 Oct 2026 03:41:17 GMT
SHA-256: 9a8c00a7987db98812ad59025733fd9d491e66316267e09a482adcb8cce1d14e
ClinGen Source details
Source release: Sat, 24 Oct 2026 08:06:31 GMT
SHA-256: 80a5e6a08b5ae87f6bad38cb2df1564fae7e038c575918f122170235748c85a4
About the library sources · Latest validated release · Record 02ed237ddd0f