A 3-year-old child presents with hypoglycemia, hepatomegaly, and lactic acidosis after overnight fasting. Liver biopsy shows massive glycogen accumulation. Enzyme assay reveals absent glucose-6-phosphatase activity. Which additional metabolic abnormality would be expected in this patient?
- A Hyperuricemia due to increased AMP degradation and decreased renal urate excretion ✓
- B Hypouricemia due to decreased purine catabolism
- C Hypolipidemia due to reduced VLDL secretion
- D Hyperkalemia due to impaired Na-K ATPase activity
Explanation
Glucose-6-phosphatase deficiency (Von Gierke disease, GSD type Ia) blocks the final step of both glycogenolysis and gluconeogenesis, trapping glucose-6-phosphate intracellularly. The accumulated G6P is shunted into glycolysis generating excess pyruvate and lactate, and into the HMP shunt increasing ribose-5-phosphate, which accelerates purine synthesis and subsequent AMP degradation to uric acid. Concomitantly, hypoglycemia-driven glucagon activates adenylate cyclase, increasing AMP catabolism; the lactic acidosis also competitively inhibits renal urate secretion, compounding hyperuricemia.
Reference: Harper's Illustrated Biochemistry, 32nd ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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