Adrenal Disorders USMLE Step 1 Practice Question
A 6-year-old boy presents with accelerated linear growth, pubic hair development, and genital enlargement. Vital signs show BP 128/82 mmHg, HR 92 bpm, RR 18, temp 37°C, SpO2 98%. Laboratory studies reveal elevated 17-hydroxyprogesterone (8.2 ng/mL), elevated DHEA-S (180 µg/dL), low cortisol (3.2 µg/dL), and elevated ACTH (68 pg/mL). Serum aldosterone is normal. Which enzyme deficiency most likely explains these findings?
Answer choices
- A21-hydroxylase deficiencyCorrect answer
- B11β-hydroxylase deficiency
- C3β-hydroxysteroid dehydrogenase deficiency
- D17α-hydroxylase deficiency
- ELipoid CAH
- FStAR protein mutation
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