<prompt> The cause of hyperuricemia and gout in glucose-6- phosphatase deficiency isMore formation of pentoseDecreased availability of glucose to tissuesIncreased accumulation of sorbitolImpaired degradation of free radicals  <response>: Purine overproduction and hyperuricemia in von Gierke disease glucose-6-phosphatase deficiency occurs secondary to enhanced generation of PRPP precursor, i.e. ribose-5-phosphate a pentose.In glucose-6-phosphatase deficiency, glucose-6-phosphate cannot be converted to glucose. Accumulated glucose-6-phosphate is then metabolized via HMP shunt, which in turn generates large amounts of ribose-5-phosphate, a precursor of PRPP. The increased synthesis of PRPP then enhances de novo synthesis of purine nucleotides. 