Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.4.2.7 (adenine phosphoribosyltransferase)
 692 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

2,8-Dihydroxyadenine (2,8-DHA) lithiasis is a form of kidney stone previously mistaken for uric acid because of identical reactivity in non-specific tests used routinely in stone analysis. Unlike uric acid, the stones crush easily and do not react with uricase. The biochemical basis for the defect is a deficiency of the enzyme adenine phosphoribosyltransferase (APRT). A complete deficiency has been reported in 29 patients from 11 countries. The number of stone formers reported in Japan (10 homozygotes, 16 heterozygotes) Austria (3), and Switzerland (2) suggests more efficient diagnosis in those countries. The defective enzyme in heterozygotes in Japan is a kinetic mutant demonstrable in intact not lysed cells. 20% of APRT-deficient subjects have been asymptomatic. An equal number have presented in acute renal failure, three of whom are now on dialysis. Formation of the nephrotoxic 2,8-DHA can be prevented by allopurinol. This underlines the importance of early diagnosis, since such severe renal damage should be avoidable.
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PMID:2,8-Dihydroxyadenine lithiasis. 378 4

A case is presented of a 41-year-old man with a history of recurrent renal stones over 10 years. Analysis of the stone showed that, although it gave a positive reaction with the non-specific phosphotungstic acid test, uricase failed to identify any urate present. Analysis in a reference laboratory confirmed its composition as dihydroxyadenine. Patients who are homozygous for the rare autosomal-recessive adenine phosphoribosyltransferase deficiency, excrete large amounts of 2,8-dihydroxyadenine, which has poor solubility at normal urinary pH. Treatment with the xanthine oxidase inhibitor allopurinol induces a total cessation of stone formation. Increased awareness of the condition and knowledge of the limitations of some methods of laboratory analysis for renal stones should help to identify this type of stone and prevent renal damage.
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PMID:2,8-Dihydroxyadenine renal stones in a 41-year-old man. 1502 10