Metabolism USMLE Step 1 Practice Question
A 5-day-old infant suffers a seizure and is rushed to the emergency department. The mother reports that the infant was healthy when born but has become extremely lethargic, and that the infant does not feed and has a strange odor. Serum studies find normal levels of glucose, acetoacetate, bicarbonate, lipids, and lactate. Which of the following, assayed in the blood of the infant, would be most useful in determining a correct diagnosis?
Answer choices
- ADicarboxylic acids
- BLysosomal hydrolases
- CAlloisoleucineCorrect answer
- DOrotic acid
- EPhenyllactate
- FMethylmalonic acid
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