ERO1B

Chr 1

endoplasmic reticulum oxidoreductase 1 beta

Also known as: ERO1LB, Ero1beta

NCBI Gene: 56605 ENSG00000086619 UniProt: Q86YB8 OMIM: 615437

This gene encodes an oxidoreductase that catalyzes disulfide bond formation in the endoplasmic reticulum by reoxidizing protein disulfide isomerase (PDI) and other disulfide isomerase family members, enabling proper protein folding. ERO1B is not constrained against loss-of-function mutations and currently has no established disease associations in humans. The protein may contribute to glucose homeostasis through its role in proinsulin folding in pancreatic cells.

OMIM ResearchSummary from RefSeq, UniProt

Enables protein-disulfide reductase activity and thiol oxidase activity. Involved in protein folding in endoplasmic reticulum. Predicted to be located in endoplasmic reticulum lumen. Predicted to be active in endoplasmic reticulum membrane. [provided by Alliance of Genome Resources, Jun 2026]

OMIM ResearchGenerating clinical summary…

Active trials

Pubs (1 yr)

—

P/LP submissions

—

P/LP missense

0.85

LOEUF

Mechanism· predicted

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD

Tolerant — LoF & missense variants common in population

LoF Constraint?

0.85LOEUF

pLI 0.000

Z-score 2.22

OE 0.58 (0.40–0.85)

Tolerant

Typical tolerance to LoF variation

Missense Constraint?

0.91Z-score

OE missense 0.83 (0.74–0.94)

198 obs / 237.5 exp

Tolerant

Mild missense constraint

Observed / Expected Ratios?

LoF OE?0.58 (0.40–0.85)

0≤0.351.4

Missense OE?0.83 (0.74–0.94)

0≤0.61.4

Synonymous OE?1.05

0≤1.21.6

LoF obs/exp: 19 / 32.7Missense obs/exp: 198 / 237.5Syn Z: -0.36

Background carrier burden — how many people carry a rare variant somewhere in ERO1B?

gnomAD v4 · ~731k individuals · PASS only

Rare means allele frequency under

Rare missense

1 in 110

549 rare PASS variants

Rare truncating (LoF)

1 in 1,100

114 rare PASS variants

Rare synonymous (reference)

1 in 250

203 rare PASS variants

Truncating variants are far rarer here than missense — that gap, in human units, is what constraint means for ERO1B. 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 190	1 in 1,400
South Asian	~43k	1 in 110	1 in 1,500
Remaining (unassigned)	~30k	1 in 89	1 in 1,100
European (Finnish)	~27k	1 in 980	1 in 1,900
Admixed American	~22k	1 in 110	1 in 990
African / African American	~21k	1 in 130	1 in 1,100
East Asian	~20k	1 in 130	1 in 570
Ashkenazi Jewish	~13k	1 in 260	1 in 2,600
Middle Eastern	~2,884	1 in 91	≈ 1 in 940

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): 6 of 16 coding exons well covered in gnomAD exomes; exons 1, 2, 3, 4, 5 and 5 more marginal. Genomes: all 16.? see exons ↓