FCGR3B
Chr 1Fc gamma receptor IIIb
Also known as: CD16, CD16-I, CD16b, FCG3, FCGR3, FCRIIIb, HNA-1
The protein encoded by this gene is a low affinity receptor for the Fc region of gamma immunoglobulins (IgG). The encoded protein acts as a monomer and can bind either monomeric or aggregated IgG. This gene may function to capture immune complexes in the peripheral circulation. Several transcript variants encoding different isoforms have been found for this gene. A highly-similar gene encoding a related protein is also found on chromosome 1. [provided by RefSeq, Aug 2012]
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Highly tolerant — LoF variants common in population
Tolerant to missense variation
This gene — mechanism propensity
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
57 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 | 1 | 0 | 0 | 1 |
Likely Pathogenic | 0 | 0 | 0 | 0 | 0 |
VUS | 0 | 35 | 0 | 0 | 35 |
Likely Benign | 0 | 5 | 1 | 4 | 10 |
Benign | 0 | 2 | 0 | 1 | 3 |
| Total | 0 | 43 | 1 | 5 | 49 |
LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly
View in ClinVar →11 pathogenic / likely-pathogenic (of 21) ClinVar copy-number / structural variants overlap FCGR3B — these span large chromosomal regions, not the gene specifically, and are excluded from the counts above. Explore in CNV tools →
Protein Context — Lollipop Plot
FCGR3B · 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