MT-CO2
Chr MTcytochrome c oxidase subunit II
Also known as: COII, MTCO2
This gene encodes cytochrome c oxidase subunit II, a core component of Complex IV of the mitochondrial respiratory chain that catalyzes the final step of electron transport and oxygen consumption. Mutations cause Complex IV deficiency presenting as encephalomyopathy with variable neurological manifestations including developmental delay, seizures, and progressive neurodegeneration. Inheritance is maternal through the mitochondrial genome, with clinical severity often correlating with the degree of heteroplasmy.
Primary Disease Associations & Inheritance
Limited evidence — not for standalone diagnostic reporting
2 total gene-disease associations curated
Population Genetics & Constraint
Constraint data not available from gnomAD.
This gene has evidence for multiple mechanisms of pathogenicity (gain-of-function and dominant-negative). Both the Badonyi & Marsh prediction and the broader genomic evidence point to gain-of-function as the predominant mechanism. Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.
Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.
Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.
ClinVar Variant Classifications
138 submitted variants in ClinVar
Classification Summary
Curated Variants Distribution
Classified variants from ClinVar · 5 ACMG categories· variant type breakdown unavailable
| Classification | LoF | Missense + Inframe | Non-coding | Synonymous | Total |
|---|---|---|---|---|---|
Pathogenic | — | — | — | — | 10 |
Likely Pathogenic | — | — | — | — | 8 |
VUS | — | — | — | — | 57 |
Likely Benign | — | — | — | — | 33 |
Benign | — | — | — | — | 29 |
| Total | — | 137 | |||
Counts from ClinVar esearch · Updated hourly
View in ClinVar →Protein Context — Lollipop Plot
MT-CO2 · protein map & ClinVar variants
Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.
External Resources
Links to major genomics databases and tools
Clinical Trials
Active and recruiting trials from ClinicalTrials.gov
No active trials found for this gene.
Search ClinicalTrials.gov →External Resources
Links to major genomics databases and tools