Metabolism USMLE Step 1 Practice Question
A 4-month-old boy presents with tremulousness and irritability occurring before feeds. Vital signs show HR 145 bpm, RR 28/min, BP 85/52 mmHg, temperature 37.2Ā°C. Physical examination reveals protuberant abdomen and hepatomegaly; no jaundice noted. After 4-hour fast, blood glucose is 32 mg/dL. Laboratory studies demonstrate lactic acidosis (pH 7.21, lactate 8 mEq/L), hyperuricemia (9.2 mg/dL), and hypertriglyceridemia (450 mg/dL). Which enzyme deficiency most likely explains these findings?
Answer choices
- ALysosomal alpha galactosidase A
- BGlucose 6 phosphataseCorrect answer
- CAcid alpha glucosidase
- DMuscle glycogen phosphorylase
- EDebranching enzyme
- FHepatic glucokinase
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