IEMbase 0544: MCEE-related methylmalonic aciduria 3
Scope
| Field | Value |
|---|---|
| IEMbase ID | 544 |
| Nosology | 1.2.2.01 |
| Gene | MCEE |
| External IDs | OMIM:251120; ORPHA:308425 |
| Generated mapping | CANDIDATE; Methylmalonic_Acidemia.yaml |
| Candidate DisMech targets | Broad Methylmalonic_Acidemia.yaml context only |
| Review date | 2026-07-07 |
IEMbase phenotype signal
IEMbase represents MCEE-related methylmalonic aciduria due to methylmalonyl-CoA epimerase deficiency, with alternate labels methylmalonic aciduria 3 and MMAE. The record is autosomal recessive, marked as a benign form, and treatability is unknown. The treatment row lists protein restriction during stress.
The phenotype signal is deliberately sparse: increased urinary methylmalonic acid is the characteristic biochemical row, and the only clinical row states no clinical significance across age periods.
DisMech phenotype coverage
Methylmalonic_Acidemia.yaml provides useful broad context for methylmalonic
acid accumulation and propionate-pathway disease, but it does not currently
model MCEE, methylmalonyl-CoA epimerase deficiency, or the benign MMAE subtype.
The local entry focuses on MMUT and adenosylcobalamin-handling defects such as
MMAA and MMAB, with recurrent metabolic decompensation, kidney disease,
neurologic injury, cardiomyopathy, C3 propionylcarnitine, methylcitric acid,
and crisis-management logic.
That coverage is much more severe and mechanistically different from the IEMbase MCEE record.
Concordance and completeness
Judgement: partial broad context only; do not treat the generated candidate as an exact MCEE mapping.
IEMbase and DisMech overlap on methylmalonic acid elevation, but IEMbase is a gene-specific, benign epimerase-deficiency record. The current local MMA entry does not include the MCEE mechanism or the low-clinical-significance scope.
Curation actions
- Do not collapse this record into the existing MMA entry as an exact match.
- If MCEE is in scope, add a methylmalonic aciduria 3 / MMAE subtype or a small standalone MCEE target under methylmalonic acidemia context.
- Preserve urinary methylmalonic acid, benign/no-clinical-significance wording, autosomal recessive inheritance, and stress protein-restriction as prompts.