A 15-year-old boy presents with hypertension and salt-water retention. He is suspected to have 17-alpha hydroxylase deficiency. What is the expected serological profile?

Appeared in: INI-CET EXAM -2026

Explanation

17-alpha hydroxylase deficiency is a form of congenital adrenal hyperplasia (CAH) where the enzyme needed to produce cortisol and sex hormones (androgens) is absent.
This enzymatic block shunts the steroid production pathway towards mineralocorticoids, leading to an excess of deoxycorticosterone (DOC), which causes sodium and water retention.
The excess mineralocorticoid activity from DOC is responsible for the clinical presentation of hypertension and salt retention.
As the pathways to produce cortisol and androgens are blocked, their levels are consequently low.

Option A: This is incorrect because the 17-alpha hydroxylase enzyme is necessary for the synthesis of both cortisol and androgens. A deficiency leads to low levels of both hormones.
Option B: This is incorrect because cortisol synthesis is blocked in 17-alpha hydroxylase deficiency, leading to low cortisol levels.
Option D: This is incorrect because the steroid precursors are shunted into the mineralocorticoid pathway, leading to an excess of mineralocorticoid activity, not a deficiency. The patient's hypertension is a direct result of this excess.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pathophysiology and hormonal profile of 17-alpha hydroxylase deficiency as background academic context rather than a clinical decision trigger.
Nurses must prioritize monitoring blood pressure and serum electrolytes (especially potassium) in patients with suspected CAH, as severe hypertension and hypokalemia can be life-threatening.
This condition presents differently based on genetic sex: males often have ambiguous genitalia (undervirilization), while females present with primary amenorrhea and lack of secondary sexual development at puberty.
Patient and family education is crucial regarding lifelong hormone replacement therapy (glucocorticoids to suppress ACTH and sex hormones for pubertal development) and the need for stress dosing of steroids.

How to Approach the Question

First, identify the core condition from the stem: 17-alpha hydroxylase deficiency.
Recall the function of this enzyme in the adrenal steroid synthesis pathway. It is a critical step for producing both glucocorticoids (cortisol) and androgens.
Deduce the direct consequence of the enzyme's absence: the products it helps create (cortisol and androgens) will be low.
Consider the effect on the precursor hormones. When a pathway is blocked, the substances 'upstream' are shunted to an alternative, open pathway. In this case, precursors are diverted to the mineralocorticoid synthesis pathway.
Connect the hormonal changes to the clinical signs. The resulting excess of mineralocorticoids (like deoxycorticosterone) explains the hypertension and salt-water retention.
Synthesize the findings: High mineralocorticoid, Low cortisol, Low androgen. Match this profile to the given options.

Concept Tested & Keywords

Concept Tested: Pathophysiology and hormonal profile of 17-alpha hydroxylase deficiency.
Stem keywords: 17-alpha hydroxylase deficiency, hypertension, salt-water retention, serological profile
Lead-in keywords: What is the expected
Clinical cues: 15-year-old boy
Clinical cues: hypertension and salt-water retention suggest mineralocorticoid excess

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E6 Nelson Textbook of Pediatrics(2024) — Volume 2 pp. 1274-1276, 1275-1277

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