Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.4.2.8 (hypoxanthine-guanine phosphoribosyltransferase)
 2,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 40-year-old normouricemic (5.5 mg/dl) male showed 46% hemolysate and 37% lymphoblast hypoxanthine phosphoribosyltransferase (HPRT) activities but was otherwise completely free of symptoms. His genomic DNA and cDNA had a missense base substitution (CAT-to-CGT in codon 60) leading to the amino-acid substitution His-to-Arg. Western blot analysis revealed that the amount of HPRT protein in lymphoblasts from this individual was 25%-50% of normal cells, suggesting that the decrease in the amount of enzyme protein was responsible for the partial deficiency. This provides the first clear evidence that a genomic missense mutation at the HPRT locus leads to a decrease in the amount of the enzyme protein but that otherwise it has no evident adverse effects in the hemizygote (asymptomatic mutation).
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PMID:An asymptomatic germline missense base substitution in the hypoxanthine phosphoribosyltransferase (HPRT) gene that reduces the amount of enzyme in humans. 900 84

The hypoxanthine-guanine phosphoribosyltransferase deficiency is an inborn error of purine metabolism, linked to the X chromosome. The clinical phenotypes associated with HPRT deficiency varied according to the level of enzyme deficiency, with a large spectrum of neurologic features like self-injurious behaviour in patients with complete deficiency. We report a 20-year-old man who had asymmetric polyarthritis, tophi, hyperuricemia, nephrolithiasis and mild neurologic symptoms with undetectable levels of HPRT activity in lysed erythrocytes. The genetic study identified the c.143G>A mutation in exon 3, GAA CGT (CTT>GAA CAT CTT (48arg>his). The presence of gouty arthropathy and chronic hyperuricemia in a young patient with neurological symptoms, suggests HPRT deficiency for which it is necessary its enzyme and molecular determination.
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PMID:Hypoxanthine-guanine phosphoribosyltransferase deficiency in a patient with a Madrid II mutation. 2299 96