Metabolism USMLE Step 1 Practice Question
A 7-month-old girl with fair skin and microcephaly presents with developmental delay and recurrent vomiting. Parents report a distinctive musty odor to her diapers and note she has not achieved normal developmental milestones. Vital signs: HR 118, RR 28, Temp 37.2°C. Examination reveals eczema and hepatomegaly. Plasma phenylalanine is markedly elevated at 18 mg/dL (normal <2). She has not received newborn screening. Which of the following is the most likely diagnosis?
Answer choices
- APhenylketonuriaCorrect answer
- BTyrosinemia type I
- CHomocystinuria
- DMaple syrup urine disease
- EAlkaptonuria
- FGalactosemia
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