Most common Enzyme Deficiency leading to childhood hypeension is
Hmm, childhood hypertension can be caused by various conditions, but enzyme deficiencies are less common. The most common ones I remember are related to the renin-angiotensin-aldosterone system (RAAS). Let me think... There's congenital adrenal hyperplasia, which involves 21-hydroxylase deficiency. That's a common one. Wait, but does that cause hypertension?
Wait, 21-hydroxylase deficiency in congenital adrenal hyperplasia can lead to different types. The salt-wasting form might cause hyponatremia and hypotension, but the non-classic form might not. Oh, wait, maybe it's 11β-hydroxylase deficiency. That's another enzyme in the cortisol pathway. When that's deficient, there's accumulation of 11-deoxycorticosterone, which is a mineralocorticoid. So that would cause hypertension, hypokalemia, and metabolic alkalosis. That's a classic presentation. So 11β-hydroxylase deficiency is a cause of hypertension in children.
Alternatively, there's 17α-hydroxylase deficiency. That blocks both cortisol and sex hormone synthesis. The excess of mineralocorticoids like deoxycorticosterone would cause hypertension. But I think 11β-hydroxylase is more common. Let me check. Yes, congenital adrenal hyperplasia due to 11β-hydroxylase deficiency is an autosomal recessive disorder that leads to hypertension in children. The other options might be other enzyme deficiencies like aldosterone synthase deficiency, but that's rarer.
So the core concept here is that 11β-hydroxylase deficiency in congenital adrenal hyperplasia is a common enzyme deficiency causing childhood hypertension. The correct answer would be C. 11β-hydroxylase deficiency. The other options are other enzyme deficiencies that either don't cause hypertension or are less common. For example, 21-hydroxylase deficiency typically causes salt-wasting or non-classic forms but not hypertension. 17α-hydroxylase deficiency is another cause, but less common. Aldosterone synthase is also a possibility but less so. So the answer is 11β-hydroxylase deficiency.
**Core Concept**
This question tests knowledge of enzyme deficiencies in the adrenal steroidogenesis pathway that lead to hypertension in children. The key mechanism involves disrupted cortisol or mineralocorticoid synthesis, causing excess mineralocorticoid precursors to exert hypertensive effects.
**Why the Correct Answer is Right**
**11β-Hydroxylase deficiency** (CYP11B1) is the most common enzyme deficiency causing childhood hypertension. It blocks cortisol synthesis, leading to accumulation of **11-deoxycorticosterone (DOC)**, a mineralocorticoid with weak sodium-retaining effects. Excess DOC causes **hypertension**, **hypokalemia**, and **metabolic alkalosis** due to increased renal sodium retention and potassium excretion. This autosomal recessive disorder is part of congenital adrenal hyperplasia (CAH