Features include always present findings: Ataxia, Generalized hypotonia, Failure to thrive, and Nystagmus and others; and common findings: Feeding difficulties in infancy, Hyperprolinemia, Enlarged spleen (splenomegaly), and Hyperalaninemia and others.

COX10 encodes cytochrome c oxidase assembly factor heme A:farnesyltransferase COX10 (443 aa). Converts protoheme IX and farnesyl diphosphate to heme O Highest expression in Testis (36.0 TPM) and Muscle Skeletal (28.6 TPM).

Mitochondrial complex IV deficiency, nuclear type 3 is associated with mutations in the COX10 gene on chromosome 17.

The COX10 protein participates in COX10 transforms heme to heme O, Metallochaperone inserts 2Cu2+ into MT-CO2, and Metallochaperone inserts Cu2+ into MT-CO1 pathways.

COX10 is classified as a druggable target with score 52.2.

Genetic testing for COX10 is available. Testing is considered confirmatory for diagnosis.

Phenotype severity distribution: 17 always present features, 9 common features.

No clinical trials have been registered for mitochondrial complex IV deficiency, nuclear type 3.

3 publications have been identified in PubMed for mitochondrial complex IV deficiency, nuclear type 3. Research spans Basic Science / Preclinical (67%) and Case Report / Case Series (33%).

Recent Publications

• Smith TB (2025). [PMID: 39701103](https://pubmed.ncbi.nlm.nih.gov/39701103/). *Am J Hum Genet*. [Basic Science / Preclinical]

• Ahola S (2024). [PMID: 39093974](https://pubmed.ncbi.nlm.nih.gov/39093974/). *Sci Adv*. [Basic Science / Preclinical]

• Tavasoli A (2024). [PMID: 38846886](https://pubmed.ncbi.nlm.nih.gov/38846886/). *Ann Med Surg (Lond)*. [Case Report / Case Series]