GNG13

Chr 16

G protein subunit gamma 13

Also known as: G(gamma)13, HG3J, h2-35

NCBI Gene: 51764 ENSG00000127588 UniProt: Q9P2W3

Heterotrimeric G proteins, which consist of alpha (see MIM 139320), beta (see MIM 139380), and gamma subunits, function as signal transducers for the 7-transmembrane-helix G protein-coupled receptors. GNG13 is a gamma subunit that is expressed in taste, retinal, and neuronal tissues and plays a key role in taste transduction (Li et al., 2006 [PubMed 16473877]).[supplied by OMIM, Oct 2009]

Active trials

Pathogenic / LP

ClinVar variants

Pubs (1 yr)

-0.5

Missense Z

1.95

LOEUF

Clinical Summary— GNG13

⚡

Population Constraint (gnomAD)

Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.

📋

ClinVar Variants

47 Pathogenic / Likely Pathogenic· 35 VUS of 87 total submissions

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD

Tolerant — LoF & missense variants common in population

LoF Constraint?LOEUF (Loss-of-function Observed/Expected Upper bound Fraction) is the upper bound of the 90% CI for LoF OE — the preferred gnomAD v4 metric. Lower = more intolerant to LoF. LOEUF < 0.35 = highly constrained.

1.95LOEUF

pLI 0.000

Z-score -1.15

OE 1.73 (0.77–1.95)

Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint?Missense Z-score: standard deviations fewer missense variants observed vs. expected. Z > 3.09 (p < 0.001) = gene does not tolerate missense variation. OE missense < 0.6 is also considered constrained.

-0.47Z-score

OE missense 1.21 (0.96–1.53)

49 obs / 40.6 exp

Tolerant

Tolerant to missense variation

Observed / Expected Ratios?Shaded band = 90% confidence interval. Vertical tick = point estimate. Grey threshold line = gnomAD constraint cutoff for that variant class.

LoF OE?Ratio of observed to expected LoF variants. Upper CI bound (LOEUF) ≤ 0.35 = strong LoF constraint signal.1.73 (0.77–1.95)

0≤0.351.4

Missense OE?Ratio of observed to expected missense variants. OE ≤ 0.6 = fewer missense variants than expected by chance.1.21 (0.96–1.53)

0≤0.61.4

Synonymous OE?Control metric — synonymous variants are largely neutral and expected near OE = 1.0. Significant deviation may indicate annotation issues.1.47

0≤1.21.6

LoF obs/exp: 5 / 2.9Missense obs/exp: 49 / 40.6Syn Z: -1.53

0.76top 25%

GOF

0.85top 5%

LOF

0.3261th %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.