A 12-day-old female infant is brought with vomiting, poor feeding, and dehydration. Examination shows ambiguous genitalia with clitoromegaly. Serum sodium is 124 mEq/L, potassium is 6.8 mEq/L, and random glucose is 58 mg/dL. The enzyme deficiency causing this presentation also results in accumulation of which precursor?
- A 11-deoxycorticosterone
- B 17-hydroxyprogesterone ✓
- C Dehydroepiandrosterone sulfate
- D Pregnenolone
Correct answer: B. 17-hydroxyprogesterone
Explanation
The combination of salt-wasting crisis with hyponatremia, hyperkalemia, hypoglycemia, and virilization in a newborn indicates classic 21-hydroxylase deficiency, the commonest form of congenital adrenal hyperplasia. Blocked conversion of 17-hydroxyprogesterone to 11-deoxycortisol causes marked elevation of 17-hydroxyprogesterone, which is the diagnostic marker on newborn screening. Option A accumulates in 11-beta-hydroxylase deficiency, which produces hypertension instead of salt wasting because 11-deoxycorticosterone has mineralocorticoid activity.
Reference: Williams Textbook of Endocrinology, 14th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.