COQ4

Chr 9AR

coenzyme Q4

Also known as: CGI-92, COQ10D7, SPAX10

NCBI Gene: 51117 ENSG00000167113 UniProt: Q9Y3A0 OMIM: 612898

The protein functions as a lyase that catalyzes C1-decarboxylation of 4-hydroxy-3-methoxy-5-(all-trans-decaprenyl)benzoic acid to 2-methoxy-6-(all-trans-decaprenyl)phenol during ubiquinone biosynthesis. Autosomal recessive mutations cause primary coenzyme Q10 deficiency type 7 and spastic ataxia 10 through disruption of the coenzyme Q10 biosynthetic pathway. Loss of function mutations result in cellular energy defects due to impaired mitochondrial electron transport chain function.

GeneReviews OMIM ResearchSummary from OMIM, UniProt

This gene encodes a component of the coenzyme Q biosynthesis pathway. Coenzyme Q, an essential component of the electron transport chain, shuttles electrons between complexes I or II to complex III of the mitochondrial transport chain. This protein appears to play a structural role in stabilizing a complex that contains most of the coenzyme Q biosynthesis enzymes. Mutations in this gene are associated with mitochondrial disorders linked to coenzyme Q deficiency. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Apr 2015]

GeneReviews OMIM ResearchGenerating clinical summary…

Primary Disease Associations & Inheritance

Coenzyme Q10 deficiency, primary, 7MIM #616276

Spastic ataxia 10, autosomal recessiveMIM #620666

Clinical highlights

Gene–disease validity (ClinGen)

Definitive · mitochondrial disease · AR · ClinGen 2023

Interpreting a novel variant

Loss of function is the curated mechanism (Gene2Phenotype), though the gene is not strongly LoF-constrained in the population — weigh truncating variants against that tolerance.Curated gene-level mechanism — a prior for triage, not a per-variant call.

Active trials

Pubs (1 yr)

—

P/LP submissions

—

P/LP missense

—

LOEUF

LOF

Mechanism· G2P

📖

GeneReview available — COQ4

Authoritative clinical overview · Recommended first read

Open GeneReview ↗

Some data sources returned errors (1)

gnomad: Error: Service overloaded

Population Genetics & Constraint

gnomAD

Constraint data not available from gnomAD.

Background carrier burden — how many people carry a rare variant somewhere in COQ4?

gnomAD v4 · ~731k individuals · PASS only

Rare means allele frequency under

Rare missense

1 in 110

477 rare PASS variants

Rare truncating (LoF)

1 in 1,200

98 rare PASS variants

Rare synonymous (reference)

1 in 150

248 rare PASS variants

Truncating variants are far rarer here than missense — that gap, in human units, is what constraint means for COQ4. 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 130	1 in 1,500
South Asian	~43k	1 in 240	1 in 1,000
Remaining (unassigned)	~30k	1 in 78	1 in 1,400
European (Finnish)	~27k	1 in 270	1 in 2,900
Admixed American	~22k	1 in 88	1 in 930
African / African American	~21k	1 in 99	1 in 990
East Asian	~20k	1 in 76	1 in 720
Ashkenazi Jewish	~13k	1 in 1,600	none seen
Middle Eastern	~2,884	1 in 180	≈ 1 in 960

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 7 coding exons well covered in gnomAD exomes and genomes.? see exons ↓