Hypertension with androgenisation of a female child is a feature of congenital adrenal hyperplasia due to deficiency of-
**Core Concept**
Congenital adrenal hyperplasia (CAH) is a group of inherited disorders that affect the adrenal glands, leading to impaired production of cortisol and aldosterone. The deficiency of specific enzymes in the steroidogenesis pathway results in the accumulation of precursors, which are then shunted towards the production of androgens.
**Why the Correct Answer is Right**
The correct answer is related to the 21-hydroxylase enzyme, which is crucial for the conversion of 17-hydroxyprogesterone to 11-deoxycortisol in the late steps of cortisol synthesis. In its deficiency, the precursor 17-hydroxyprogesterone is shunted towards the production of androgens, resulting in androgenization of female children. This is the most common form of CAH, accounting for approximately 90-95% of cases.
**Why Each Wrong Option is Incorrect**
* **Option A:** 17,20-desmolase deficiency is a rare form of CAH that affects the conversion of 17-hydroxyprogesterone to androstenedione, but it is not the most common form associated with androgenization in female children.
* **Option B:** 3-beta-hydroxysteroid dehydrogenase (3-beta-HSD) deficiency is another form of CAH that affects the conversion of pregnenolone to progesterone and 17-hydroxyprogesterone to 11-deoxycortisol, but it is less common than 21-hydroxylase deficiency.
* **Option C:** 11-beta-hydroxylase deficiency is a form of CAH that affects the conversion of 11-deoxycortisol to cortisol, resulting in an overproduction of deoxycorticosterone and its mineralocorticoid metabolites, but it is not typically associated with androgenization in female children.
**Clinical Pearl / High-Yield Fact**
The classic presentation of 21-hydroxylase deficiency includes hypertension, hypokalemia, and androgenization in female children. The mnemonic "HHA" can be used to remember these features: Hypertension, Hypokalemia, and Androgenization.
**Correct Answer: C. 11-beta-hydroxylase deficiency is incorrect. The correct answer is actually D. 21-hydroxylase deficiency.**
**Correct Answer: D. 21-hydroxylase deficiency.