National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Gamma aminobutyric acid transaminase deficiency



Other Names:
GABA transaminase deficiency; Gamma aminobutyrate transaminase deficiency; GABAT; GABA transaminase deficiency; Gamma aminobutyrate transaminase deficiency; GABAT; 4 alpha aminobutyrate transaminase deficiency; ABAT See More
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GABA (gamma-aminobutyric acid) is an important molecule which slows down the activity of cells in the brain.[1] GABA is broken down in the body by a substance known as 4-aminobutyrate aminotransferase, also known as GABA-transaminase or GABA-T.[1] Mutations in the ABAT gene can cause less GABA-T to be made, a condition known as GABA-T deficiency.[1] The symptoms for an individual with GABA-T deficiency can include: psychomotor retardation (a slowing down of thought and activity), low muscle tone, hyperactive responses, lethargy, seizures, and EEG abnormalities.[1] GABA-T deficiency is very rare, with fewer than 5 cases reported in the literature.[2] It is thought to be inherited in an autosomal recessive manner.[3][4]

Last updated: 3/20/2015

Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources


Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease


These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

In-Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Gamma aminobutyric acid transaminase deficiency. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.


  1. ABAT. Genetics Home Reference. March 2015; http://ghr.nlm.nih.gov/gene/ABAT. Accessed 3/20/2015.
  2. Parviz, M. et al.. Disorders of GABA metabolism: SSADH and GABA-transaminase deficiencies. J Pediatr Epilepsy. 2014 Nov 25; 3(4):217-227. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4256671/. Accessed 3/20/2015.
  3. GABA-TRANSAMINASE DEFICIENCY. OMIM. Dec 2009; http://omim.org/entry/613163. Accessed 3/20/2015.
  4. Pearl, P. et al. Inherited Disorders of GABA Metabolism. Future Neurol. 2006; 1(5):632-636. http://www.pndassoc.org/pdf/Pearl.pdf. Accessed 3/20/2015.