STXBP3

Chr 1

syntaxin binding protein 3

Also known as: MUNC18-3, MUNC18C, PSP, UNC-18C

NCBI Gene: 6814ENSG00000116266UniProt: O00186

Enables syntaxin binding activity. Involved in negative regulation of calcium ion-dependent exocytosis; neutrophil degranulation; and platelet aggregation. Located in cytosol; plasma membrane; and secretory granule. [provided by Alliance of Genome Resources, Jul 2025]

85
ClinVar variants
17
Pathogenic / LP
0.00
pLI score
0
Active trials
Clinical Summary— STXBP3
⚡
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.
📋
ClinVar Variants
17 Pathogenic / Likely Pathogenic· 66 VUS of 85 total submissions
Some data sources returned errors (2)

omim: Error: OMIM fetch failed: 429

pubmed: Error: NCBI fetch failed: 429 https://eutils.ncbi.nlm.nih.gov/entrez/eutils/esummary.fcgi

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD
Moderate LoF intolerance
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.
0.59LOEUF
pLI 0.000
Z-score 3.49
OE 0.38 (0.25–0.59)
Moderately constrained

More LoF-intolerant than ~75% of genes

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.
1.76Z-score
OE missense 0.71 (0.64–0.80)
216 obs / 302.3 exp
Tolerant

Mild missense constraint

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.0.38 (0.25–0.59)
0≤0.351.4
Missense OE?Ratio of observed to expected missense variants. OE ≤ 0.6 = fewer missense variants than expected by chance.0.71 (0.64–0.80)
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.0.85
0≤1.21.6
LoF obs/exp: 14 / 36.9Missense obs/exp: 216 / 302.3Syn Z: 1.18

ClinVar Variant Classifications

85 submitted variants in ClinVar

ClinVar

Classification Summary

Pathogenic12
Likely Pathogenic5
VUS66
Likely Benign2
12
Pathogenic
5
Likely Pathogenic
66
VUS
2
Likely Benign

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
0
0
12
0
12
Likely Pathogenic
2
1
2
0
5
VUS
1
55
10
0
66
Likely Benign
0
2
0
0
2
Benign
0
0
0
0
0
Total35824085

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

View in ClinVar →

Protein Context — Lollipop Plot

STXBP3 · protein map & ClinVar variants

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

OMIM — Genotype-Phenotype

OMIM

No OMIM entries found.

Clinical Literature
Landmark / reviewRecent case evidence
Recent Gene-Specific Literature
Gene in title · MEDLINE · newest first
Europe PMC
Top 5 resultsSearch Europe PMC ↗

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

ClinicalTrials.gov

No active trials found for this gene.

Search ClinicalTrials.gov →

External Resources

Links to major genomics databases and tools