This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
[{'content': 'The cause of hyperuricemia and gout in glucose-6- phosphatase deficiency is \nSelect and explain. \nA. More formation of pentose, B. Decreased availability of glucose to tissues, C. Increased accumulation of sorbitol, D. Impaired degradation of free radicals', 'role': 'user'}, {'content': 'Answer: A \nExplanation: 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).\nIn 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.', 'role': 'assistant'}]