Inborn errors of purine metabolism represent relatively new disorders. The first genetic, metabolic, purine disorder was described in 1954, and in 1967 a genetic basis for gout in childhood or adolescence was recognized. The number of enzyme defects identified since then has increased rapidly. Clinical features are diverse and non-specific. Clinical presentation can involve the renal system (urolithiasis, renal failure, interstitial nephritis), nervous system (seizures, psychomotor retardation, choreoathetosis, selfmutilation), joints (gouty arthritis) as well as haemopoietic and immune systems. Although these are generally paediatric problems, some disorders can become manifest at any time from birth to the 80s. Although some are relatively benign, others can have serious consequences. Understandably, knowledge at the clinical level has been unable to keep pace with biochemical and genetic findings, a problem compounded by the broad spectrum of presentation and genetic heterogeneity. Their recent description means that awareness is limited and they can be be frequently misdiagnosed, or remain undiagnosed – particularly in adults where such defects are being recognised as the basis of costly, life-threatening illness. Recent advances increasingly implicate these defects in adults as well as children. Consequently, effort is required to alert physicians to the broad spectrum of clinical presentation. The most frequent disorders are complete deficiency of hypoxanthine-phosphoribosyltransferase (HPRT) and familial juvenile hyperuricaemic nephropathy (FJHN). The clinical and laboratory findings indicating detailed purine metabolic investigations are: gout – particularly in youngs individuals, in girls and young women; kidney disorder with hyper- or hypouricaemia; selfmutilation; immunodeficiency; unexplained psychomotor retardation or hypotonia or seizures; lithiasis with family history; muscle pain after exercise; deafness with hyperuricaemia, hyperuricaemia-particularly with exclusion of secondary causes, hypouricaemia. The proper indication of purine investigation and detection of the new cases will not only help a number of patient, but is almost certain to illuminate further pathogenesis of these disorders.

        Key words: purine, inborn errors of metabolism, hyperuricaemia, hypouricaemia, gout.