STXBP2
Chr 19ARsyntaxin binding protein 2
Also known as: Hunc18b, MUNC18-2, UNC18-2, UNC18B, pp10122, unc-18B
The protein regulates cytotoxic granule exocytosis in natural killer cells by controlling SNARE complex assembly and vesicle fusion with membranes. Mutations cause familial hemophagocytic lymphohistiocytosis, an autosomal recessive disorder affecting the immune system. The gene is highly intolerant to loss-of-function variants (pLI near 0), consistent with severe disease when both copies are affected.
Definitive — sufficient evidence for diagnostic panels
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Typical tolerance to LoF variation
Mild missense constraint
ClinVar Variant Classifications
100 submitted variants in ClinVar
Classification Summary
Curated Variants Distribution
Classified variants from ClinVar · 5 ACMG categories
| Classification | LoF | Missense + Inframe | Non-coding | Synonymous | Total |
|---|---|---|---|---|---|
Pathogenic | 5 | 0 | 0 | 0 | 5 |
Likely Pathogenic | 1 | 0 | 0 | 0 | 1 |
VUS | 1 | 29 | 3 | 0 | 33 |
Likely Benign | 0 | 2 | 25 | 7 | 34 |
Benign | 0 | 0 | 0 | 0 | 0 |
Conflicting | — | 1 | |||
| Total | 7 | 31 | 28 | 7 | 74 |
LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly
View in ClinVar →Protein Context — Lollipop Plot
STXBP2 · 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