IEMbase 0676: FDPS-related farnesylpyrophosphate synthetase deficiency
Scope
| Field | Value |
|---|---|
| IEMbase ID | 676 |
| Nosology | 14.7.05.01 |
| Nosology code | IEM0744 |
| Gene | FDPS |
| External IDs | OMIM:616631; ORPHA:79152 |
| Generated mapping | UNMAPPED; best candidate Carbamoyl_Phosphate_Synthetase_I_Deficiency.yaml |
| Candidate DisMech targets | Broad sterol/isoprenoid-pathway context only; no exact FDPS/POROK9 target |
| Review date | 2026-07-07 |
IEMbase phenotype signal
IEMbase represents autosomal dominant FDPS-related farnesylpyrophosphate synthetase deficiency, labeled porokeratosis type 9.
The cached phenotype signal includes characteristic actinic porokeratosis and keratotic skin lesions in adolescence and adulthood. No biochemical rows are present in the cached disease record.
DisMech phenotype coverage
No exact FDPS, farnesylpyrophosphate synthetase deficiency, or porokeratosis type 9 local target was identified.
Carbamoyl_Phosphate_Synthetase_I_Deficiency.yaml is a lexical false positive
and should not be used. It is a urea-cycle disorder and does not share the
dominant mevalonate/isoprenoid dermatologic phenotype. Mevalonate_Kinase_Deficiency.yaml
is only broad pathway context and represents a different recessive systemic
autoinflammatory disease.
Concordance and completeness
Judgement: true local gap.
The row is best interpreted as a dominant porokeratosis/keratinization disorder from a downstream mevalonate-pathway gene, not as urea-cycle disease and not as classic MVK-related mevalonate kinase deficiency.
Curation actions
- Add a dedicated FDPS/POROK9 target if this disease is curated.
- Reject CPS1 deficiency as exact coverage.
- Preserve actinic porokeratosis and keratotic skin lesions as the phenotype signal.
- Keep this grouped with the PMVK and MVD porokeratosis records if a sterol-pathway porokeratosis curation sweep is planned.