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Genetics Library / Genes / ADA2

GENE REFERENCE / HGNC:1839

ADA2

adenosine deaminase 2

protein-coding gene22q11.1Gene information

What does this gene do?

The ADA2 gene provides instructions for making an enzyme called adenosine deaminase 2. This enzyme breaks down molecules called adenosine and 2'-deoxyadenosine. Because this enzyme functions in the spaces between cells, it is described as extracellular. Another form of the enzyme, adenosine deaminase 1, breaks down the same molecules inside cells. This other version of the enzyme is produced from the ADA gene.

Researchers are still working to determine the functions of adenosine deaminase 2. Studies suggest that it acts as a growth factor, which means that it stimulates cell growth and division. In particular, the enzyme appears to be involved in the growth and development of certain immune system cells, including macrophages, which are a type of white blood cell that plays a critical role in inflammation. Inflammation is a normal immune system response to injury and foreign invaders (such as bacteria). Some macrophages are pro-inflammatory, meaning they promote inflammation, while others are anti-inflammatory, meaning they reduce inflammation.

Source: MedlinePlus, National Library of Medicine. Source publication: 2020-08-18. Source review: 2018-08.

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.

ConditionInheritanceEvidence
obsolete deficiency of adenosine deaminase 2MONDO:0100317 · Evaluated 2023-05-30Autosomal recessiveDefinitiveAntibody Deficiencies 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
715
Submissions for variants in or overlapping this gene
1,289
Submissions explicitly reporting this gene
1,194
Alleles reported pathogenic / likely pathogenic
97
VariationIDs with uncertain significance
274
VariationIDs with conflicting classifications
34

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 ↗

View this gene in ClinVar ↗

YOUR DNA FILE

Can your DNA file tell you about ADA2?

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 97 alleles in ADA2 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 ADA2.

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 2026-10-10.

HGNC Source details

Open source record ↗

Source release: Fri, 09 Oct 2026 13:40:45 GMT
Source record updated: 2024-07-15

SHA-256: e4cd9c6d7120051b80e5e61d2aeb98bd6a541ddd21f428a6eab922c11242e053

MedlinePlus Source details

Open source record ↗

Source release: Sat, 10 Oct 2026 05:16:07 GMT
Source publication: 2020-08-18
Source review: 2018-08

SHA-256: fdc8bd614310c12718379cef6569962e5d0e791cecabcc355b53a72816ac263a

ClinVar Source details

Open source record ↗

Source release: Sun, 04 Oct 2026 13:15:29 GMT

SHA-256: 126d9e5bded1d43c0380ac6684c86f9aab056d2ff2be93d743e408ed917ae558

ClinGen Source details

Open source record ↗

Source release: Sat, 10 Oct 2026 09:49:14 GMT

SHA-256: 5bbc9404c72cc21d80e36ea4c49380231755850af5c34064262adceb74881af6

About the library sources · Latest validated release · Record 5f3499cf1465