IEMbase 0149: PNP-related purine nucleoside phosphorylase deficiency
Scope
| Field | Value |
|---|---|
| IEMbase ID | 149 |
| Nosology | 16.2.09.01 |
| Gene | PNP |
| External IDs | OMIM:613179; OMIM:164050; ORPHA:760 |
| Generated mapping | UNMAPPED |
| Candidate DisMech targets | No valid PNP deficiency target found; IKBKG/IMD33 candidate is false |
| Review date | 2026-07-07 |
IEMbase phenotype signal
IEMbase represents this as PNP-related purine nucleoside phosphorylase deficiency, with alternate label T-cell immunodeficiency and abbreviation PNP. Treatability is marked yes.
The biochemical rows include decreased red-cell purine nucleoside phosphorylase activity, increased plasma and urinary deoxyguanosine, increased plasma and urinary deoxyinosine, and decreased plasma and urinary uric acid. Clinical rows include T-cell immunodeficiency, recurrent infections, decreased CD4-positive cells, developmental delay, spastic diplegia, and tetraparesis.
DisMech phenotype coverage
No local PNP/purine nucleoside phosphorylase deficiency entry was found. The
generated best candidate, IKBKG_Ectodermal_Dysplasia_with_Immunodeficiency.yaml
via an IMD33 label, is not valid: IKBKG-related immunodeficiency is an NF-kB
signaling disorder, not a purine nucleoside phosphorylase enzyme deficiency.
Mentions of PNPT1/PNPase or thiopurine metabolism elsewhere in the KB do not provide disease-level coverage for PNP deficiency.
Concordance and completeness
Judgement: true unmapped local disease gap.
The IEMbase record has a distinctive purine salvage and T-cell immunodeficiency signature: low PNP enzyme activity, deoxyguanosine/deoxyinosine accumulation, low uric acid, recurrent infections, T-cell deficiency, and neurologic motor involvement. Current DisMech has adjacent purine-metabolism and immunodeficiency content but not this disease.
Curation actions
- Keep this record unmapped.
- Reject the IKBKG/IMD33 candidate as an immunodeficiency-label false positive.
- Future curation should add PNP deficiency with purine nucleoside metabolite accumulation, low uric acid, T-cell immunodeficiency, recurrent infections, developmental delay, spastic diplegia, and tetraparesis.