Objective: Hyperuricaemia is a frequent laboratory finding in children and adults, in a wide range of acquired or genetically-based metabolic diseases. Among the most frequent reasons for hyperuricaemia is excessive production of purines de novo, accelerated degradation or decreased interconversions of purine nucleotides and decreased renal excretion of uric acid. Setting: Institute of Inherited Metabolic Disorders, General Faculty Hospital and Charles University First Faculty of Medicine. Material and Method: Within the scope of selective screening for inherited metabolic disorders conducted from 1995 till 2002 in the Czech Republic, blood and/or urine level of the uric acid was investigated approximately in 17 000 cases in a group of 24 000 patients. Purine metabolites had been monitored in 3 000 patients. Results: Various inherited metabolic disorders as the reason for hyperuricaemia were found in 82 patients. Twenty patients suffered from familial juvenile hyperuricaemic nephropathy. Deficient activity of hypoxantine-guaninephosphoribosyltransferase was found in 14 patients, glycogenosis type I in 20, glycogenosis type III in 5, glykogenosis type VI in 4 and glykogenosis type IX in 19 patients. Conclusions: Differential diagnostics of patients suffering hyperuricemia is rather wide and in order to correctly discover the diagnosis a cooperation with specialized laboratory is necessary. Metabolic, enzymatic and molecular analyses may significantly contribute both to the recognition of the etiology of hyperuricemia and to the monitoring of the patient’s compliance.

        Key words: hyperuricaemia, hypoxanthin phosphoribosyltransferase, Lesch-Nyhan syndrome, phosphoribosylpyrophosphate synthetase (ribose-phosphate pyrophosphokinase), glykogen storage disease, familial juvenile hyperuricaemic nephropathy.