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IEMbase 0712: TTC19-related mitochondrial complex III deficiency, nuclear type 2

Scope

Field Value
IEMbase ID 712
Nosology 7.3.02.02
Nosology code IEM0459
Gene TTC19
External IDs OMIM:615157; ORPHA:1460
Generated mapping CANDIDATE to COX11-Related_COX_Deficiency.yaml
Candidate DisMech targets No exact TTC19/MC3DN2 target identified
Review date 2026-07-07

IEMbase phenotype signal

IEMbase represents autosomal recessive TTC19-related mitochondrial complex III deficiency, nuclear type 2. MONDO resolves this disease to the TTC19-specific term mitochondrial complex III deficiency nuclear type 2 with OMIM:615157.

The cached phenotype rows show neonatal low-to-normal plasma glucose, increased plasma lactate from neonatal through childhood windows, possible basal ganglia MRI abnormalities and developmental delay from infancy onward, gait ataxia from infancy through adulthood, possible neonatal hypoglycemia, and neonatal metabolic acidosis.

DisMech phenotype coverage

No exact TTC19 or MC3DN2 local target was identified.

The generated COX11-Related_COX_Deficiency.yaml candidate is a complex IV copper-delivery disorder, not complex III TTC19 disease. Local CoQ10 and ETFDH/MADD entries mention electron transfer into or through complex III, and HIDEA_Syndrome.yaml includes unrelated complex III activity findings, but none of these are exact TTC19 complex III deficiency coverage.

Concordance and completeness

Judgement: true local complex III gap. The COX11 candidate should be rejected.

The IEMbase row points to a TTC19-specific complex III disorder with lactate, basal ganglia/developmental findings, ataxia, hypoglycemia, and metabolic acidosis. A complex IV COX entry is not an acceptable mapping despite respiratory-chain overlap.

Curation actions

  • Add a dedicated TTC19/MC3DN2 target if curated.
  • Reject COX11-Related_COX_Deficiency.yaml as exact coverage.
  • Preserve lactate, low-to-normal glucose, hypoglycemia, metabolic acidosis, basal ganglia MRI abnormalities, developmental delay, and gait ataxia.
  • Keep complex III deficiency distinct from complex IV COX deficiency.