GAD1
Chr 2ARglutamate decarboxylase 1
Also known as: CPSQ1, DEE89, GAD, GAD-67, SCP
This enzyme catalyzes the synthesis of gamma-aminobutyric acid (GABA), the brain's primary inhibitory neurotransmitter, using pyridoxal 5'-phosphate as a cofactor. Autosomal recessive mutations cause developmental and epileptic encephalopathy 89, characterized by pyridoxine-dependent seizures due to deficient GABA production. Loss of enzyme function reduces inhibitory neurotransmission, leading to seizure susceptibility that responds to pyridoxine supplementation.
Definitive — sufficient evidence for diagnostic panels
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
More LoF-intolerant than ~75% of genes
Moderately missense-constrained (top ~2.5%)
Predictions shown for reference only — model trained on dominant genes, not applicable to AR conditions.
The Badonyi & Marsh prediction model was trained exclusively on dominant disease genes. Predictions are not reliable for genes with autosomal recessive inheritance and are shown at reduced opacity for reference only.
Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.
ClinVar Variant Classifications
0 submitted variants in ClinVar
Protein Context — Lollipop Plot
GAD1 · protein map & ClinVar variants
Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.
3D Protein StructureAlphaFold
External Resources
Links to major genomics databases and tools
Clinical Trials
Active and recruiting trials from ClinicalTrials.gov
No active trials found for this gene.
Search ClinicalTrials.gov →External Resources
Links to major genomics databases and tools