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IEMbase 0737: MT-CO3-related cytochrome c oxidase subunit 3 deficiency

Scope

Field Value
IEMbase ID 737
Nosology 6.1.03.01
Nosology code IEM0464
Gene MT-CO3
External IDs OMIM:516050; ORPHA:99845
Generated mapping UNMAPPED; weak candidate COX4I1-Related_COX_Deficiency.yaml
Candidate DisMech targets No exact MT-CO3 target identified
Review date 2026-07-07

IEMbase phenotype signal

IEMbase represents mitochondrial MT-CO3-related cytochrome c oxidase subunit 3 deficiency. The cached rows emphasize elevated plasma lactate from infancy through adulthood, myopathy and muscle weakness from childhood through adulthood, possible childhood Leigh syndrome, and possible psychomotor retardation from infancy through adolescence.

DisMech phenotype coverage

No exact MT-CO3 local target was identified.

The generated COX4I1-Related_COX_Deficiency.yaml candidate should be treated as a pathway neighbor only. COX4I1 is a nuclear-encoded complex IV subunit with autosomal recessive genetics and a COX4-1 structural/regulatory mechanism; it is not the mtDNA-encoded COX3 disease represented by IEMbase. Existing complex IV module/grouping content provides reusable context but not an MT-CO3 disease entry.

Concordance and completeness

Judgement: true MT-CO3 mtDNA-encoded complex IV gap. The local COX4I1 entry is not an exact mapping.

IEMbase is useful for future curation because it separates the MT-CO3 phenotype from adjacent complex IV subunit disorders and captures lactate, myopathy, weakness, possible Leigh syndrome, and psychomotor delay.

Curation actions

  • Add a dedicated MT-CO3 cytochrome c oxidase subunit 3 deficiency target if curated.
  • Reject COX4I1-Related_COX_Deficiency.yaml as exact coverage.
  • Preserve lactate, myopathy, weakness, Leigh-syndrome, and psychomotor-delay prompts.