RAB27B
Chr 18RAB27B, member RAS oncogene family
Also known as: C25KG
RAB27B encodes a small GTPase that regulates intracellular membrane trafficking, vesicle transport, and late endocytic pathway homeostasis, including facilitating axonal transport of neurotrophin receptors. Mutations cause Zimmermann-Laband syndrome, a rare disorder characterized by facial dysmorphism, intellectual disability, and distinctive features including gingival overgrowth and nail dysplasia. The condition follows an autosomal dominant inheritance pattern.
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Typical tolerance to LoF variation
Mild missense constraint
This gene has evidence for multiple mechanisms of pathogenicity (dominant-negative and gain-of-function). Both the Badonyi & Marsh prediction and the broader genomic evidence point to dominant-negative as the predominant mechanism. Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.
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
91 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 | 0 | 0 | 55 | 0 | 55 |
Likely Pathogenic | 0 | 0 | 2 | 0 | 2 |
VUS | 0 | 23 | 4 | 0 | 27 |
Likely Benign | 0 | 1 | 0 | 0 | 1 |
Benign | 0 | 0 | 0 | 0 | 0 |
| Total | 0 | 24 | 61 | 0 | 85 |
LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly
View in ClinVar →Protein Context — Lollipop Plot
RAB27B · protein map & ClinVar variants
Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.
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