IEMbase 0706: MT-ND2-related NADH dehydrogenase core subunit 2 deficiency
Scope
| Field | Value |
|---|---|
| IEMbase ID | 706 |
| Nosology | 6.1.19.01 |
| Nosology code | IEM0431 |
| Gene | MT-ND2 |
| External IDs | OMIM:252010; ORPHA:255210 |
| Generated mapping | UNMAPPED; weak generated candidate to Pyruvate_Dehydrogenase_Deficiency.yaml |
| Candidate DisMech targets | Broad complex I/Leigh context only; no exact MT-ND2 target |
| Review date | 2026-07-07 |
IEMbase phenotype signal
IEMbase represents maternally inherited MT-ND2-related NADH dehydrogenase core subunit 2 deficiency.
Biochemical rows show decreased fibroblast complex I activity and increased plasma lactate across all age windows, plus low-to-normal plasma glucose in neonatal and infantile windows. Clinical rows include exercise intolerance from infancy through adulthood and adolescent/adult Leber hereditary optic neuropathy. Characteristic rows add neonatal-to-childhood Leigh syndrome and ragged red fibers across all age windows.
DisMech phenotype coverage
No exact MT-ND2 local target was identified.
Leigh_Syndrome.yaml covers the broad syndrome-level relationship between
complex I dysfunction and Leigh-spectrum disease. It does not model MT-ND2,
ragged red fibers, or the LHON/exercise-intolerance presentation as a
gene-specific disease. No exact LHON target was identified.
The weak generated Pyruvate_Dehydrogenase_Deficiency.yaml candidate is not an
mtDNA complex I subunit disease and should not be treated as coverage.
Concordance and completeness
Judgement: true local gap with broad Leigh overlap only.
The IEMbase signal is a combined complex I deficiency, LHON, Leigh, and mitochondrial myopathy/ragged-red-fiber phenotype. That phenotype package is not represented by a local MT-ND2 target.
Curation actions
- Add a dedicated MT-ND2 complex I deficiency target if curated.
- Reject pyruvate dehydrogenase deficiency as exact coverage.
- Preserve decreased complex I activity, increased lactate, low-to-normal neonatal/infantile glucose, exercise intolerance, LHON, Leigh syndrome, and ragged red fibers.