APRT deficiency is reported in all ethnic groups, but the majority of studies are from Japan, Iceland, and France.
APRT deficiency can present at any age (Bollee et al.
A diagnosis of APRT deficiency should be considered in all children presenting with renal colic, recurrent radiolucent kidney stones, or acute kidney injury, and in infants presenting with reddish-brown diaper stains.
Urine microscopy will usually show characteristic small and round, brown DHA crystals, which are pathognomonic of APRT deficiency.
Patients with APRT deficiency Type I will have no APRT activity in red cell lysates and functionally significant mutations in both copies of the APRT gene.
Early recognition of APRT deficiency and prompt initiation of pharmacologic therapy can help stabilize renal function and prevent further renal damage.
For example, the present study has used two online tasks, a SPRT and an APRT
A proton nuclear magnetic resonance (1H-NMR) spectrometric method can be used to measure many compounds of purine and pyrimidine metabolism (13), but it has a major disadvantage in that it fails to detect uric acid and 2,8-dihydroxyadenine, which are very useful markers for the diagnosis of APRT deficiency, XDH deficiency, molybdenum cofactor deficiency, PRPPS super-activity, and HGPRT deficiency.
This method can be used to correctly diagnose deficiencies of APRT, ADA, PNP, UMPS, ASL, TP, DPD, DHP, UP, XDH, molybdenum cofactor, PRPPS, and HGPRT.
4] Nonstandard abbreviations: PRPPS, phosphoribosyl pyrophosphate synthetase; HGPRT, hypoxanthine guanine phosphoribosyl transferase; PNP, purine nucleoside phosphorylase; XDH, xanthine dehydrogenase; APRT, adenine phosphoribosyl transferase; ADA, adenosine deaminase; UMPS, uridine monophosphate synthase; ASL, adenylosuccinate lyase; TP, thymidine phosphorylase; UP, [beta]-ureidopropionase; DHP, dihydropyrimidinase; DPD, dihydropyrimidine dehydrogenase; ESI MS/MS, electrospray ionization tandem mass spectrometry; and SAICAR, succinyl-5-amino-4-imidazole carboxamide riboside.
APRT deficiency was the only enzyme defect in purine metabolism where no abnormality could be observed in the urinary [sup.
1]H-NMR, proton nuclear magnetic resonance; CSF, cerebrospinal fluid; TSP, trimethylsilyl-2,2,3,3-tetradeuteropropionic acid, sodium salt; SAICA, succinylaminoimidazole carboxamide; APRT, adenine phosphoribosyltransferase; XDH, xanthine dehydrogenase; AO, aldehyde oxidase; HGPRT, hypoxanthine-guanine phosphoribosyltransferase; ADA, adenosine deaminase; and PNP, purine-nucleoside phosphorylase.