The ADAR gene provides instructions for making a protein called RNA-specific adenosine deaminase 1 (ADAR1). This protein is involved in making changes to (editing) ribonucleic acid (RNA), a chemical cousin of DNA. Specifically, it attaches (binds) to RNA and changes an RNA building block (nucleotide) called adenosine to another nucleotide called inosine.
The ADAR1 protein is involved in the control of the innate immune response, which is the immune system's early response to foreign invaders (pathogens). The adenosine-to-inosine editing performed by ADAR1 is thought to change certain areas of the body's own RNA that the immune system might interpret as belonging to a virus that should be attacked. In this way, the protein helps the immune system avoid inappropriate targeting of the body's own tissues.
The ADAR1 protein is also thought to inhibit the replication and spread of certain viruses, such as human immunodeficiency virus (HIV) and hepatitis C, by modifying their RNA. In addition, the ADAR1 protein controls the function of certain chemical messengers called neurotransmitters at particular sites in the body by modifying the RNA blueprint for receptor proteins that interact with the neurotransmitters. Studies suggest that the ADAR1 protein may have other functions that are not well understood.
Health Conditions Related to Genetic Changes
At least 30 ADAR gene mutations have been identified in people with Aicardi-Goutières syndrome, a disorder that involves severe brain dysfunction (encephalopathy), skin lesions, immune system abnormalities, and other health problems. Some of these mutations lead to an ADAR1 protein that is less able to bind to RNA; others impair the protein's RNA editing function. As a result, control of the immune response is impaired and the immune system attacks the body's own tissues and organs, leading to the signs and symptoms of Aicardi-Goutières syndrome.More About This Health Condition
More than 180 ADAR gene mutations have been identified in people with dyschromatosis symmetrica hereditaria. This disorder is characterized by freckle-like spots (macules) on the face, hands, and feet that are darker or lighter than surrounding skin, generally appearing in infancy or early childhood.
The ADAR gene mutations that cause dyschromatosis symmetrica hereditaria result in less functional ADAR1 protein. While the function of this protein in the skin is unknown, researchers suggest that incorrect RNA editing may result in pigment-producing cells (melanocytes) that are more or less active than normal, resulting in the skin spots that occur in this disorder.
ADAR gene mutations have also been identified in individuals with various neurological problems that differ from those that occur in Aicardi-Goutières syndrome, and without the other signs and symptoms that occur in that disorder.
Other Names for This Gene
- 136 kDa double-stranded RNA-binding protein
- adenosine deaminase acting on RNA 1-A
- dsRNA adenosine deaminase
- dsRNA adeonosine deaminase
- interferon-induced protein 4
- interferon-inducible protein 4
Additional Information & Resources
Tests Listed in the Genetic Testing Registry
Scientific Articles on PubMed
- Crow YJ. Aicardi-Goutières Syndrome. 2005 Jun 29 [updated 2016 Nov 22]. In: Adam MP, Ardinger HH, Pagon RA, Wallace SE, Bean LJH, Stephens K, Amemiya A, editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2020. Available from http://www.ncbi.nlm.nih.gov/books/NBK1475/ Citation on PubMed
- Fisher AJ, Beal PA. Effects of Aicardi-Goutières syndrome mutations predicted from ADAR-RNA structures. RNA Biol. 2017 Feb;14(2):164-170. doi: 10.1080/15476286.2016.1267097. Epub 2016 Dec 12. Review. Citation on PubMed or Free article on PubMed Central
- Hayashi M, Suzuki T. Dyschromatosis symmetrica hereditaria. J Dermatol. 2013 May;40(5):336-43. doi: 10.1111/j.1346-8138.2012.01661.x. Epub 2012 Sep 14. Review. Citation on PubMed
- Heraud-Farlow JE, Walkley CR. The role of RNA editing by ADAR1 in prevention of innate immune sensing of self-RNA. J Mol Med (Berl). 2016 Oct;94(10):1095-1102. Epub 2016 Apr 5. Review. Citation on PubMed
- Liddicoat BJ, Chalk AM, Walkley CR. ADAR1, inosine and the immune sensing system: distinguishing self from non-self. Wiley Interdiscip Rev RNA. 2016 Mar-Apr;7(2):157-72. doi: 10.1002/wrna.1322. Epub 2015 Dec 21. Review. Citation on PubMed
- Pestal K, Funk CC, Snyder JM, Price ND, Treuting PM, Stetson DB. Isoforms of RNA-Editing Enzyme ADAR1 Independently Control Nucleic Acid Sensor MDA5-Driven Autoimmunity and Multi-organ Development. Immunity. 2015 Nov 17;43(5):933-44. doi: 10.1016/j.immuni.2015.11.001. Citation on PubMed or Free article on PubMed Central
- Rice GI, Kasher PR, Forte GM, Mannion NM, Greenwood SM, Szynkiewicz M, Dickerson JE, Bhaskar SS, Zampini M, Briggs TA, Jenkinson EM, Bacino CA, Battini R, Bertini E, Brogan PA, Brueton LA, Carpanelli M, De Laet C, de Lonlay P, del Toro M, Desguerre I, Fazzi E, Garcia-Cazorla A, Heiberg A, Kawaguchi M, Kumar R, Lin JP, Lourenco CM, Male AM, Marques W Jr, Mignot C, Olivieri I, Orcesi S, Prabhakar P, Rasmussen M, Robinson RA, Rozenberg F, Schmidt JL, Steindl K, Tan TY, van der Merwe WG, Vanderver A, Vassallo G, Wakeling EL, Wassmer E, Whittaker E, Livingston JH, Lebon P, Suzuki T, McLaughlin PJ, Keegan LP, O'Connell MA, Lovell SC, Crow YJ. Mutations in ADAR1 cause Aicardi-Goutières syndrome associated with a type I interferon signature. Nat Genet. 2012 Nov;44(11):1243-8. doi: 10.1038/ng.2414. Epub 2012 Sep 23. Citation on PubMed or Free article on PubMed Central
- Rice GI, Kitabayashi N, Barth M, Briggs TA, Burton ACE, Carpanelli ML, Cerisola AM, Colson C, Dale RC, Danti FR, Darin N, De Azua B, De Giorgis V, De Goede CGL, Desguerre I, De Laet C, Eslahi A, Fahey MC, Fallon P, Fay A, Fazzi E, Gorman MP, Gowrinathan NR, Hully M, Kurian MA, Leboucq N, Lin JS, Lines MA, Mar SS, Maroofian R, Martí-Sanchez L, McCullagh G, Mojarrad M, Narayanan V, Orcesi S, Ortigoza-Escobar JD, Pérez-Dueñas B, Petit F, Ramsey KM, Rasmussen M, Rivier F, Rodríguez-Pombo P, Roubertie A, Stödberg TI, Toosi MB, Toutain A, Uettwiller F, Ulrick N, Vanderver A, Waldman A, Livingston JH, Crow YJ. Genetic, Phenotypic, and Interferon Biomarker Status in ADAR1-Related Neurological Disease. Neuropediatrics. 2017 Jun;48(3):166-184. doi: 10.1055/s-0037-1601449. Epub 2017 Apr 10. Citation on PubMed
- Zipeto MA, Jiang Q, Melese E, Jamieson CH. RNA rewriting, recoding, and rewiring in human disease. Trends Mol Med. 2015 Sep;21(9):549-59. doi: 10.1016/j.molmed.2015.07.001. Epub 2015 Aug 7. Review. Citation on PubMed