GABRB3

Chr 15AD

gamma-aminobutyric acid type A receptor subunit beta3

Also known as: DEE43, ECA5, EIEE43

The protein is the beta-3 subunit of GABA(A) receptors, heteropentameric ligand-gated chloride channels that mediate GABAergic inhibition in the brain by allowing chloride influx and reducing neuronal excitability. Mutations cause developmental and epileptic encephalopathy 43 and childhood absence epilepsy through an autosomal dominant inheritance pattern. The gene is highly intolerant to loss-of-function variants, and mutations can cause disease through multiple mechanisms depending on the specific variant.

GeneReviewsOMIMResearchSummary from RefSeq, OMIM, UniProt
MultiplemechanismADLOEUF 0.342 OMIM phenotypes
Clinical SummaryGABRB3
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Gene-Disease Validity (ClinGen)
developmental and epileptic encephalopathy · ADDefinitive

Definitive — sufficient evidence for diagnostic panels

Population Constraint (gnomAD)
Highly constrained gene — heterozygous loss-of-function variants are very rare in the population (pLI 0.95). One damaged copy is likely sufficient to cause disease.
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ClinVar Variants
116 unique Pathogenic / Likely Pathogenic· 220 VUS of 500 total submissions
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GeneReview available — GABRB3
Authoritative clinical overview · Recommended first read
Open GeneReview ↗

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Dual constrained — LoF & missense intolerant
LoF Constraint
0.34LOEUF
pLI 0.951
Z-score 3.83
OE 0.13 (0.060.34)
Highly constrained

Highly LoF-intolerant (top ~10% of genes)

Missense Constraint
3.39Z-score
OE missense 0.41 (0.350.48)
107 obs / 260.9 exp
Constrained

Highly missense-constrained (top ~0.1%)

Observed / Expected Ratios
LoF OE0.13 (0.060.34)
00.351.4
Missense OE0.41 (0.350.48)
00.61.4
Synonymous OE1.09
01.21.6
LoF obs/exp: 3 / 22.7Missense obs/exp: 107 / 260.9Syn Z: -0.72
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
definitiveGABRB3-related childhood absence epilepsyOTHERAD
DN
0.5966th %ile
GOF
0.6832th %ile
LOF
0.56top 25%

This gene has evidence for multiple mechanisms of pathogenicity (loss-of-function and gain-of-function). The Badonyi & Marsh model scores gain-of-function highest among its predictions, but genomic evidence (constraint, ClinVar variant spectrum, and literature) most strongly supports loss-of-function (haploinsufficiency). Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.

LOF16% of P/LP variants are LoF · LOEUF 0.34
GOFprediction above median · 1 literature citation

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.

Literature Evidence

GOFGain-of-function GABRB3 variants identified in vigabatrin-hypersensitive epileptic encephalopathies.PMID:33585817

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312. Mechanism ranking also informed by gnomAD constraint, ClinVar, and ClinGen data.

ClinVar Variant Classifications

500 submitted variants in ClinVar

Classification Summary

Pathogenic77
Likely Pathogenic39
VUS220
Likely Benign133
Benign10
Conflicting11
77
Pathogenic
39
Likely Pathogenic
220
VUS
133
Likely Benign
10
Benign
11
Conflicting

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
12
10
55
0
77
Likely Pathogenic
7
30
2
0
39
VUS
11
182
26
1
220
Likely Benign
0
6
60
67
133
Benign
0
5
5
0
10
Conflicting
11
Total3023314868490

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

View in ClinVar →

Protein Context — Lollipop Plot

GABRB3 · 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 →