Diabetes Mellitus USMLE Step 1 Practice Question
A 5-day-old female infant with ambiguous external genitalia presents with lethargy and poor feeding. Vital signs reveal BP 68/42 mmHg, HR 158/min, RR 32/min, temperature 36.8°C. Laboratory studies demonstrate hyponatremia (128 mEq/L), hyperkalemia (6.2 mEq/L), low cortisol (2 mcg/dL), low aldosterone, and elevated 17-hydroxyprogesterone (450 ng/dL). Glucose is normal. No history of maternal virilization. Which enzyme deficiency most likely explains these findings?
Answer choices
- A11 beta hydroxylase
- BCholesterol desmolase
- CAromatase
- D21 hydroxylaseCorrect answer
- E17 alpha hydroxylase
- F3 beta hydroxysteroid dehydrogenase
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