Gene
ADA
adenosine deaminase
- HGNC 186(opens in a new tab)
- Ensembl gene ENSG00000196839(opens in a new tab)
- NCBI Gene 100(opens in a new tab)
Summary
- Cytogenetic location
- 20q13.12
- Coordinates
- Chromosome 20: 44,619,522–44,651,699 (GRCh38)
- Exons
- 12 exons across 32.2 kb
- Protein
- 363 amino acids
- Inheritance
- Autosomal recessive
- Also known as
- ADA1
- MANE Select transcript
- ENST00000372874.9NM_000022.4
- Locus type
- gene with protein product
- Very high
- Confident
- Low
- Very low
Reference genomeGRCh38hg38
Positions on gene and variant pages follow this choice, in this browser.
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Get my Genome TestCurated reports relevant to this gene
Severe Combined Immunodeficiency
- Autosomal recessive
Severe combined immunodeficiency (SCID) comprises a group of rare monogenic primary immunodeficiency disorders characterized by a lack of functional peripheral T lymphocytes resulting in early-onset severe respiratory infections and failure to thrive. They are classified according to immunological phenotype into SCID with absence of T cells but presence of B cells (T-B+ SCID) or SCID with absence of both (T-B- SCID). Both of these groups include several forms, with or without natural killer (NK) cells.
- ClinGen rates the link definitive
- 6 GenCC submitters rate it definitive or strong
Broader groupings
Other Inborn Errors of Immunity
- Immunodeficiency Disease
One of 170 genes linked to it
Disease in which there is a deficiency or defect in the mechanisms of immunity, either cellular or humoral.
- ClinGen rates the link definitive
- 6 GenCC submitters rate it definitive or strong
What knowing changes
HSCT for SCID and severe PIDs; immunoglobulin replacement (IVIG/SCIG) for antibody deficiencies; leniolisib (Joenja, FDA 2023) for APDS; gene therapy for ADA-SCID; abatacept for CTLA4/LRBA deficiency; prophylactic antibiotics; G-CSF for CGD
Inheritance
- Autosomal recessive
- It takes a changed copy from each parent. With one, you are a carrier and usually unaffected; when both parents are carriers, each child has a one-in-four chance of inheriting two.
Trait report that reads ADA
Sleep & Chronotype
- Deep-Sleep Depth
How ADA is laid out
- Coding sequence
- Untranslated region
- Intron
- Direction of transcription
- Known disease-causing sites
- Stretches short reads find hard
- Variants with a page
Exons of the gene's MANE Select transcript (release v1.5), from NCBI and EMBL-EBI, on the GRCh38 reference genome.
Chromosome bands from UCSC's GRCh38 ideogram (2022-10-29).
Nearby genes from Ensembl release 116, on GRCh38.
Exons make up 1.5 kb of the gene's 32.2 kb; 1,092 of those bases code for the protein.
How a genome test reads ADA
143
positions in ADA where ClinVar classes a change as pathogenic or likely pathogenic
None of them falls in a region short reads find hard.
A whole genome covers all 32.2 kb of ADA, introns included, not only the 1.5 kb of exons.
Variants with a page (27)
The ADA variants with a page here, most review stars first. Each page describes ClinVar's public record of the variant, never a result.
| Variant | HGVS c. | Exon or intron | Position (GRCh38) | ClinVar classification | Review status |
|---|---|---|---|---|---|
| A329V | c.986C>T | Exon 11 | 44,620,391 | Pathogenic | 3 stars out of 4 reviewed by expert panel |
| c.219-2A>G | Intron 3 | 44,626,601 | Likely pathogenic | 3 stars out of 4 reviewed by expert panel | |
| c.363-2A>G | Intron 4 | 44,625,686 | Likely pathogenic | 3 stars out of 4 reviewed by expert panel | |
| c.603C>A | Exon 6 | 44,624,205 | Likely pathogenic | 3 stars out of 4 reviewed by expert panel | |
| c.606+1G>T | Intron 6 | 44,624,201 | Likely pathogenic | 3 stars out of 4 reviewed by expert panel | |
| c.975+1G>A | Intron 10 | 44,621,017 | Pathogenic | 3 stars out of 4 reviewed by expert panel | |
| c.976-1G>C | Intron 10 | 44,620,402 | Pathogenic | 3 stars out of 4 reviewed by expert panel | |
| c.1078+2T>A | Intron 11 | 44,620,297 | Likely pathogenic | 3 stars out of 4 reviewed by expert panel | |
| E255X | c.763G>T | Exon 8 | 44,622,846 | Likely pathogenic | 3 stars out of 4 reviewed by expert panel |
| G216R | c.646G>A | Exon 7 | 44,623,039 | Pathogenic | 3 stars out of 4 reviewed by expert panel |
Traits linked to ADA
The Human Phenotype Ontology lists these as features of the rare conditions ADA can cause. Each trait's page lists the other genes linked to it.
External links
Gene records
Transcript
Protein
Where this comes from
- HGNC: the gene's symbol, name, other symbols and location.
- MANE Select v1.5, from NCBI and EMBL-EBI: the transcript, its exons and coding sequence.
- GenCC and ClinGen, released 2026-10-16: which conditions the gene is linked to, and how strongly.
- The ACMG secondary findings list, SF v3.2.
- ClinVar and the GIAB stratifications: known disease-causing sites, and the regions short reads find hard.
- The Human Phenotype Ontology, release 2026-09-01: the traits linked to the gene. Find out more at hpo.jax.org.
- Data release 2026.10.16-c6eea6bf.
Cite this page
Dante Labs. (n.d.). ADA gene: adenosine deaminase. Retrieved 16 October 2026, from https://dantelabs.com/genes/ada
Dante Labs. ADA gene: adenosine deaminase [Internet]. [cited 16 October 2026]. Available from: https://dantelabs.com/genes/ada
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