FCER1G

Chr 1

Fc epsilon receptor Ig

Also known as: FCRG

NCBI Gene: 2207 ENSG00000158869 UniProt: P30273 OMIM: 147139

The high affinity IgE receptor is a key molecule involved in allergic reactions. It is a tetramer composed of 1 alpha, 1 beta, and 2 gamma chains. The gamma chains are also subunits of other Fc receptors. [provided by RefSeq, Jul 2008]

OMIM Research

OMIM ResearchGenerating clinical summary…

Clinical highlights

Interpreting a novel variant

This gene is strongly intolerant of loss-of-function variation in the population, so LoF variants warrant close attention. No curated mechanism annotation is available — see the mechanism card for the computational prediction and its caveats.Based on population constraint only.

Active trials

Pubs (1 yr)

—

P/LP submissions

—

P/LP missense

0.61

LOEUF

Multiple*

Mechanism· predicted

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD

Moderate LoF intolerance

LoF Constraint?

0.61LOEUF

pLI 0.663

Z-score 2.26

OE 0.13 (0.04–0.61)

Moderately constrained

Typical tolerance to LoF variation

Missense Constraint?

-0.02Z-score

OE missense 1.01 (0.79–1.29)

45 obs / 44.6 exp

Tolerant

Tolerant to missense variation

Observed / Expected Ratios?

LoF OE?0.13 (0.04–0.61)

0≤0.351.4

Missense OE?1.01 (0.79–1.29)

0≤0.61.4

Synonymous OE?0.85

0≤1.21.6

LoF obs/exp: 1 / 7.8Missense obs/exp: 45 / 44.6Syn Z: 0.51

Background carrier burden — how many people carry a rare variant somewhere in FCER1G?

gnomAD v4 · ~731k individuals · PASS only

Rare means allele frequency under

Rare missense

1 in 210

117 rare PASS variants

Rare truncating (LoF)

1 in 3,100

22 rare PASS variants

Rare synonymous (reference)

1 in 1,800

43 rare PASS variants

Truncating variants are far rarer here than missense — that gap, in human units, is what constraint means for FCER1G. A background rate for each class, not the frequency of any particular variant; thin-coverage exons undercount.

By genetic ancestry · 9 gnomAD groups · rare = under 0.1% in that group

Group	People	Missense	Truncating
European (non-Finnish)	~556k	1 in 300	1 in 3,700
South Asian	~43k	1 in 950	≈ 1 in 43,000
Remaining (unassigned)	~30k	1 in 270	≈ 1 in 10,000
European (Finnish)	~27k	1 in 610	≈ 1 in 27,000
Admixed American	~22k	1 in 250	≈ 1 in 11,000
African / African American	~21k	1 in 310	1 in 2,500
East Asian	~20k	1 in 420	≈ 1 in 20,000
Ashkenazi Jewish	~13k	1 in 1,100	≈ 1 in 13,000
Middle Eastern	~2,884	≈ 1 in 2,900	none seen

Each group is summed over the variants that are rare in that group. Grey ≈ figures rest on fewer than five expected carriers — too few to distinguish groups. Differences mostly reflect how many people were sampled and how much variation each ancestry carries, not disease risk.

Exome coverage (gnomAD): All 5 coding exons well covered in gnomAD exomes and genomes.? see exons ↓