GABRG3

Chr 15

gamma-aminobutyric acid type A receptor subunit gamma3

The GABRG3 protein is a gamma subunit of GABA-A receptors, pentameric ligand-gated chloride channels that mediate inhibitory neurotransmission in the brain and contain the benzodiazepine binding site. Mutations cause autosomal recessive epileptic encephalopathy with intellectual disability and developmental delays. This gene is highly constrained against loss-of-function variants (pLI 0.85, LOEUF 0.39), indicating that such mutations are likely to have significant clinical consequences.

OMIMResearchSummary from RefSeq, UniProt
MultiplemechanismLOEUF 0.39
Clinical SummaryGABRG3
Population Constraint (gnomAD)
Moderately constrained gene (pLI 0.85) — some intolerance to loss-of-function variants.
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ClinVar Variants
305 unique Pathogenic / Likely Pathogenic· 51 VUS of 373 total submissions

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Moderate LoF intolerance
LoF Constraint
0.39LOEUF
pLI 0.847
Z-score 3.76
OE 0.17 (0.080.39)
Moderately constrained

More LoF-intolerant than ~75% of genes

Missense Constraint
2.52Z-score
OE missense 0.56 (0.490.64)
145 obs / 259.1 exp
Mild constraint

Moderately missense-constrained (top ~2.5%)

Observed / Expected Ratios
LoF OE0.17 (0.080.39)
00.351.4
Missense OE0.56 (0.490.64)
00.61.4
Synonymous OE1.02
01.21.6
LoF obs/exp: 4 / 23.8Missense obs/exp: 145 / 259.1Syn Z: -0.17
DN
0.6840th %ile
GOF
0.72top 25%
LOF
0.4135th %ile

This gene has evidence for multiple mechanisms of pathogenicity (gain-of-function and dominant-negative). Both the Badonyi & Marsh prediction and the broader genomic evidence point to gain-of-function as the predominant mechanism. Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.

GOFprediction above median
DNprediction above median

Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.

ClinVar Variant Classifications

373 submitted variants in ClinVar

Classification Summary

Pathogenic297
Likely Pathogenic8
VUS51
Likely Benign4
Benign4
297
Pathogenic
8
Likely Pathogenic
51
VUS
4
Likely Benign
4
Benign

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
0
0
296
1
297
Likely Pathogenic
0
0
8
0
8
VUS
1
37
12
1
51
Likely Benign
0
4
0
0
4
Benign
0
0
1
3
4
Total1413175364

LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly

View in ClinVar →

Protein Context — Lollipop Plot

GABRG3 · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

3D Protein StructureAlphaFold

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

Search ClinicalTrials.gov →
Clinical Literature
Open Research Assistant →
Recent Gene-Specific Literature
Gene in title · MEDLINE · newest first
Europe PMC