[Inherited disorders of uric acid metabolism--classification, enzymatic- and DNA-diagnosis]

Uric acid is the end product of purine metabolism in human. Then, the enzymatic abnormalities, concerning purine metabolism, cause disorders of uric acid metabolism including hyperuricemia and hypouricemia. The superactivity of 5-phosphoribosyl-pyrophosphate (PRPP) synthetase and deficiency of hypoxanthine-guanine phosphoribosyltransferase (HGPRT) caused hyperuricemia. In glycogen storage diseases of type I, III, V, and VII, decreased energy supply induces hyperuricemia by accelerating ATP degradation. Deficiencies of xanthine oxidase (XO), purine nucleoside phosphorylase (PNP), and PRPP were reported causing hypouricemia. Many methods for DNA-diagnosis were developed including Southern blot, Northern blot, PCR-SSCP (polymerase chain reaction-single strand conformation polymorphism), PCR-RFLP (restriction fragment length polymorphism), and allele specific oligonucleotide hybridization etc.