PNP (Purine nucleoside phosphorylase) enzyme assay
- Description
- Purine nucleoside phosphorylase (PNP) deficiency catalyses the conversion of the purine nucleosides inosine, deoxyinosine, guanosine and deoxyguanosine to the respective bases. The enzyme is assayed in red cell lysates using inosine as the substrate with products of the reaction separated from substrate by HPLC. This test is not currently included in the laboratory's UKAS scope of accreditation to ISO15189:2022.
- Clinical details
- Inherited severe combined immunodeficiency. Children typically present with recurrent infections due to absent T-cell immunity. There may be B-cell dysfunction leading to autoimmunity. Neurological abnormalities are present in about 50% of patients. Uric acid in plasma may be low, but not always. The disorder is autosomal recessive.
- Related condition
- Reference range
3000 - 7000
- Units
- nmol/h/mgHb
- Testing site
- Synnovis : Reference Services : Blackfriars Hub
- Laboratory
- Reference Chemistry
- Sample type and volume required
- 4 mL blood EDTA (purple top)
- Storage and transport
- Store in fridge, ( don't freeze)to lab within 3 days/1st class pos
- Turnaround time
- 1 week