A 7-month-old infant is brought to the emergency department by his father due to worsening lethargy and unusual breathing after sleeping through the night without a feeding. The child has had multiple similar episodes over the past two months, often in the early morning, accompanied by sweating, irritability, and poor feeding. He has not yet started crawling. His abdomen is protuberant. On examination, he has hypotonia, with the liver edge palpable 4 cm below the costal margin. Serum studies reveal low serum glucose, and elevated lactate, uric acid, and triglycerides. Liver biopsy shows excessive glycogen accumulation with otherwise normal architecture. Which of the following best explains this patient’s condition?
Accumulation of abnormally branched glycogen due to defective branching enzyme
Deficiency of glucose-6-phosphatase impairing both glycogenolysis and gluconeogenesis
Deficiency of glucose-6-phosphatase impairing both glycogenolysis and gluconeogenesis
Impaired glycogen breakdown due to deficiency of muscle glycogen phosphorylase
Inability to degrade glycogen within lysosomes due to acid alpha-glucosidase deficiency
Milder fasting hypoglycemia due to debranching enzyme deficiency with normal lactate levels
