Home › MCQs › MBBS › Question #10347
Back to Questions
MBBS QUESTION #10347
Question 1
A child with von Gierke disease (glycogen storage disease type I) has a deficiency of glucose-6-phosphatase. This enzyme deficiency produces severe fasting hypoglycemia because:
  • Both glycogenolysis and gluconeogenesis generate glucose-6-phosphate, but without this enzyme, glucose-6-phosphate cannot be dephosphorylated to free glucose for release from the liver into the bloodstream✔️
  • Glycogen cannot be synthesized under any circumstance
  • Cellular glucose uptake is entirely blocked without this enzyme
  • This enzyme functions only in the branching of glycogen, unrelated to blood glucose release
Correct Answer Explanation
Glucose-6-phosphatase, found in liver and kidney, catalyzes the final common step required to release free glucose into the blood from either glycogenolysis or gluconeogenesis; its absence traps glucose intracellularly as glucose-6-phosphate, producing severe fasting hypoglycemia along with lactic acidosis, hyperuricemia, and hyperlipidemia from shunting of accumulated glucose-6-phosphate into alternate pathways.