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ABAT gene

4-aminobutyrate aminotransferase

Normal Function

The ABAT gene provides instructions for making the GABA-transaminase enzyme. This enzyme helps break down a brain chemical (neurotransmitter) called GABA when it is not needed. GABA normally helps slow down (inhibit) brain cell activity when necessary, to prevent the brain from being overloaded with too many signals. For this reason GABA is called an inhibitory neurotransmitter.

Health Conditions Related to Genetic Changes

GABA-transaminase deficiency

At least 10 mutations in the ABAT gene have been identified in people with GABA-transaminase deficiency, which is a brain disease (encephalopathy) that begins in infancy. Babies with this disorder have recurrent seizures (epilepsy), movement problems, and profoundly delayed development. They may grow more rapidly in length than usual (accelerated linear growth), even though they have feeding problems and may not gain weight as quickly as expected (failure to thrive). Individuals with this disorder usually do not survive past the first 2 years of life, but some live longer into childhood.

The ABAT gene mutations that cause GABA-transaminase deficiency lead to a shortage (deficiency) of functional GABA-transaminase enzyme. As a result, GABA is not properly broken down, so this neurotransmitter and another molecule called beta-alanine accumulate abnormally in brain cells. This accumulation alters the balance of neurotransmitters in the brain, leading to the neurological problems characteristic of GABA-transaminase deficiency. Excess GABA also leads to abnormal release of a protein that is necessary for growth of the body's bones and tissues (growth hormone), resulting in the accelerated linear growth that sometimes occurs in this disorder.

More About This Health Condition

Other Names for This Gene

  • (S)-3-amino-2-methylpropionate transaminase
  • 4-aminobutyrate aminotransferase, mitochondrial precursor
  • 4-aminobutyrate transaminase
  • GABA aminotransferase
  • GABA transaminase
  • GABA transferase
  • gamma-amino-N-butyrate transaminase
  • NPD009

Additional Information & Resources

Tests Listed in the Genetic Testing Registry

Scientific Articles on PubMed

Catalog of Genes and Diseases from OMIM

Gene and Variant Databases


  • Besse A, Petersen AK, Hunter JV, Appadurai V, Lalani SR, Bonnen PE. Personalized medicine approach confirms a milder case of ABAT deficiency. Mol Brain. 2016 Dec 1;9(1):93. doi: 10.1186/s13041-016-0273-8. Citation on PubMed or Free article on PubMed Central
  • Koenig MK, Hodgeman R, Riviello JJ, Chung W, Bain J, Chiriboga CA, Ichikawa K, Osaka H, Tsuji M, Gibson KM, Bonnen PE, Pearl PL. Phenotype of GABA-transaminase deficiency. Neurology. 2017 May 16;88(20):1919-1924. doi: 10.1212/WNL.0000000000003936. Epub 2017 Apr 14. Citation on PubMed or Free article on PubMed Central
  • Louro P, Ramos L, Robalo C, Cancelinha C, Dinis A, Veiga R, Pina R, Rebelo O, Pop A, Diogo L, Salomons GS, Garcia P. Phenotyping GABA transaminase deficiency: a case description and literature review. J Inherit Metab Dis. 2016 Sep;39(5):743-747. doi: 10.1007/s10545-016-9951-z. Epub 2016 Jul 4. Citation on PubMed
  • Medina-Kauwe LK, Tobin AJ, De Meirleir L, Jaeken J, Jakobs C, Nyhan WL, Gibson KM. 4-Aminobutyrate aminotransferase (GABA-transaminase) deficiency. J Inherit Metab Dis. 1999 Jun;22(4):414-27. doi: 10.1023/a:1005500122231. Citation on PubMed
  • Nagappa M, Bindu PS, Chiplunkar S, Govindaraj P, Narayanappa G, Krishnan A, Bharath MM, Swaminathan A, Saini J, Arvinda HR, Sinha S, Mathuranath PS, Taly AB. Hypersomnolence-hyperkinetic movement disorder in a child with compound heterozygous mutation in 4-aminobutyrate aminotransferase (ABAT) gene. Brain Dev. 2017 Feb;39(2):161-165. doi: 10.1016/j.braindev.2016.08.005. Epub 2016 Sep 3. Citation on PubMed
  • Pearl PL, Gibson KM. Clinical aspects of the disorders of GABA metabolism in children. Curr Opin Neurol. 2004 Apr;17(2):107-13. doi: 10.1097/00019052-200404000-00005. Citation on PubMed
  • Tsuji M, Aida N, Obata T, Tomiyasu M, Furuya N, Kurosawa K, Errami A, Gibson KM, Salomons GS, Jakobs C, Osaka H. A new case of GABA transaminase deficiency facilitated by proton MR spectroscopy. J Inherit Metab Dis. 2010 Feb;33(1):85-90. doi: 10.1007/s10545-009-9022-9. Epub 2010 Jan 6. Citation on PubMed or Free article on PubMed Central

The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.