COX18

Chr 4AR

cytochrome c oxidase assembly factor COX18

Also known as: CMT2MM, COX18HS, MC4DN25, OXA1L2

This gene encodes a mitochondrial membrane insertase that translocates cytochrome c oxidase subunit II across the mitochondrial inner membrane and is essential for respiratory chain complex IV assembly and stability. Mutations cause autosomal recessive mitochondrial complex IV deficiency and Charcot-Marie-Tooth disease type 2MM, an axonal peripheral neuropathy. The gene appears relatively tolerant to loss-of-function variants based on constraint metrics.

OMIMResearchSummary from RefSeq, OMIM, UniProt
LOFmechanismARLOEUF 1.702 OMIM phenotypes
Clinical SummaryCOX18
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.
📋
ClinVar Variants
26 unique Pathogenic / Likely Pathogenic· 62 VUS of 105 total submissions

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
1.70LOEUF
pLI 0.000
Z-score -0.70
OE 1.18 (0.831.70)
Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint
0.13Z-score
OE missense 0.97 (0.861.10)
184 obs / 189.1 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE1.18 (0.831.70)
00.351.4
Missense OE0.97 (0.861.10)
00.61.4
Synonymous OE0.96
01.21.6
LoF obs/exp: 20 / 16.9Missense obs/exp: 184 / 189.1Syn Z: 0.24
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
limitedCOX18-related peripheral neuropathyLOFAR

Predictions shown for reference only — model trained on dominant genes, not applicable to AR conditions.

DN
0.6745th %ile
GOF
0.6930th %ile
LOF
0.3550th %ile

The Badonyi & Marsh prediction model was trained exclusively on dominant disease genes. Predictions are not reliable for genes with autosomal recessive inheritance and are shown at reduced opacity for reference only.

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.

ClinVar Variant Classifications

105 submitted variants in ClinVar

Classification Summary

Pathogenic25
Likely Pathogenic1
VUS62
Likely Benign6
Benign1
25
Pathogenic
1
Likely Pathogenic
62
VUS
6
Likely Benign
1
Benign

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
0
2
23
0
25
Likely Pathogenic
0
0
1
0
1
VUS
2
54
6
0
62
Likely Benign
1
4
1
0
6
Benign
0
0
1
0
1
Total36032095

LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly

View in ClinVar →

Protein Context — Lollipop Plot

COX18 · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

3D Protein StructureAlphaFold

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

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Clinical Literature
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