HPRT – (Hypoxanthine phosphoribosyltransferase)
- Description
- HPRT catalyses the salvage of hypoxanthine to form IMP and guanine to form GMP. The enzyme is assayed in red cell lysates as the formation of IMP from the substrates hypoxanthine and phosphoribosylpyrophosphate using an HPLC based method. This test is not currently included in the laboratory's UKAS scope of accreditation to ISO15189:2022.
- Clinical details
- HPRT deficiency either partial or complete, results in hyperuricaemia due to uric acid overproduction. It is an X-linked disorder. Complete HPRT deficiency results in Lesch-Nyhan Disease (LND), characterised by hyperuricaemia, choreoathetosis, spasticity, and difficulties with speech and feeding. The hallmark of the condition is compulsive self-mutilation and aggression. There is a phenotypic spectrum with residual enzyme activity protecting against some or all neurological abnormalities including self-injurious behaviour. Patients with partial HPRT deficiency may present with gout as teenagers. Biochemical markers for HPRT are purine over production seen as an increased uric acid/creatinine ratio in urine, a raised plasma uric acid, and raised NAD levels in the red cell nucleotide profile.
- Related condition
- Reference range
80 - 130
- 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 laboratory within 3 days/1st class pos
- Turnaround time
- 1 week