COG3

Chr 13

component of oligomeric golgi complex 3

Also known as: CDG2BB, SEC34

NCBI Gene: 83548 ENSG00000136152 UniProt: Q96JB2

COG3 encodes a component of the conserved oligomeric Golgi complex that is essential for ER-Golgi transport and maintaining normal Golgi morphology and protein glycosylation. Mutations cause congenital disorder of glycosylation type IIbb with autosomal recessive inheritance. The gene is highly constrained against loss-of-function variants, indicating its critical importance in cellular function.

ResearchSummary from RefSeq, OMIM, UniProt

This gene encodes a component of the conserved oligomeric Golgi (COG) complex which is composed of eight different subunits and is required for normal Golgi morphology and localization. Defects in the COG complex result in multiple deficiencies in protein glycosylation. The protein encoded by this gene is involved in ER-Golgi transport.[provided by RefSeq, Jun 2011]

ResearchGenerating clinical summary…

Primary Disease Associations & Inheritance

UniProtCongenital disorder of glycosylation 2BB

Clinical highlights

Gene–disease validity (ClinGen)

Limited · congenital disorder of glycosylation · AR · ClinGen 2024

not for standalone diagnostic reporting

Active trials

Pubs (1 yr)

—

P/LP submissions

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P/LP missense

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LOEUF

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Mechanism

Some data sources returned errors (2)

gnomad: Error: gnomAD API error: 400

omim: Error: OMIM fetch failed: 429

Population Genetics & Constraint

gnomAD

Constraint data not available from gnomAD.

Background carrier burden — how many people carry a rare variant somewhere in COG3?

gnomAD v4 · ~731k individuals · PASS only

Rare means allele frequency under

Rare missense

1 in 99

872 rare PASS variants

Rare truncating (LoF)

1 in 4,100

75 rare PASS variants

Rare synonymous (reference)

1 in 190

385 rare PASS variants

Truncating variants are far rarer here than missense — that gap, in human units, is what constraint means for COG3. 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 110	1 in 4,600
South Asian	~43k	1 in 90	1 in 1,200
Remaining (unassigned)	~30k	1 in 96	1 in 5,000
European (Finnish)	~27k	1 in 220	1 in 3,000
Admixed American	~22k	1 in 91	1 in 3,100
African / African American	~21k	1 in 87	≈ 1 in 9,100
East Asian	~20k	1 in 59	≈ 1 in 6,600
Ashkenazi Jewish	~13k	1 in 280	≈ 1 in 13,000
Middle Eastern	~2,884	1 in 80	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.