Features include always present findings: Lethargy, High-pitched cry, Seizure, and Feeding difficulties and others; and common findings: Tall stature, Downslanted palpebral fissures, Cerebellar hypoplasia, and Agenesis of corpus callosum and others.

ABAT encodes 4-aminobutyrate aminotransferase (500 aa). Catalyzes the conversion of gamma-aminobutyrate and L-beta-aminoisobutyrate to succinate semialdehyde and methylmalonate semialdehyde, respectively. Highest expression in Brain Frontal Cortex BA9 (98.8 TPM) and Brain Nucleus accumbens basal ganglia (98.5 TPM).

GABA aminotransaminase deficiency is associated with mutations in the ABAT gene on chromosome 16.

ABAT is classified as a druggable target (Druggable Genome and Enzyme categories) with score 0.9.

54 pathogenic variants reported in ABAT in ClinVar.

Genetic testing for ABAT is available. Testing is considered confirmatory for diagnosis.

Phenotype severity distribution: 7 always present features, 8 common features.

Estimated prevalence: <1 in 1,000,000 (VERY_RARE).

No clinical trials have been registered for GABA aminotransaminase deficiency.

4 publications have been identified in PubMed for GABA aminotransaminase deficiency. Research spans Basic Science / Preclinical (75%) and Case Report / Case Series (25%).

Recent Publications

• Alammary D (2026). [PMID: 41573381](https://pubmed.ncbi.nlm.nih.gov/41573381/). *JIMD reports*. [Case Report / Case Series]

• Holmes-Léon G (2026). [PMID: 41819842](https://pubmed.ncbi.nlm.nih.gov/41819842/). *J Neurosci*. [Basic Science / Preclinical]

• Ambrosini G (2025). [PMID: 40414180](https://pubmed.ncbi.nlm.nih.gov/40414180/). *Molecular genetics and metabolism*. [Basic Science / Preclinical]

• Zou Z (2024). [PMID: 39133003](https://pubmed.ncbi.nlm.nih.gov/39133003/). *Applied and environmental microbiology*. [Basic Science / Preclinical]