Okay, let's tackle this question. The user is asking about hypokalemic hypertension being a feature of which condition. The correct answer is option C, which is Gitelman syndrome.

First, I need to recall the core concept here. Hypokalemic hypertension is associated with conditions that cause excessive loss of potassium, leading to increased renin-angiotensin-aldosterone system (RAAS) activity. This system is crucial in regulating blood pressure and electrolyte balance.

Gitelman syndrome is a genetic disorder affecting the thiazide-sensitive Na-Cl cotransporter in the distal convoluted tubule. This leads to impaired sodium reabsorption, causing hypokalemia, hypomagnesemia, and metabolic alkalosis. The activation of RAAS due to sodium loss results in hypertension in some cases, though it's not always present.

Now, looking at the other options. Option A might be Liddle's syndrome, which is a cause of hypertension but is characterized by hyperkalemia due to aldosterone-independent sodium retention. So, it doesn't fit hypokalemic hypertension. Option B could be Cushing's syndrome, where cortisol excess leads to hypertension but typically with hypokalemia only in some cases like adrenal tumors. However, Cushing's is more associated with hyperglycemia and other features. Option D might be Bartter syndrome, which also causes hypokalemia but is more severe and presents in infancy, with normal or low blood pressure, unlike Gitelman's which is milder and presents later.

The clinical pearl here is that Gitelman syndrome is often underdiagnosed and presents with a triad of hypokalemia, hypomagnesemia, and metabolic alkalosis, with normal to low blood pressure in some, but when hypertension is present, it's due to RAAS activation. It's important to differentiate from Bartter and Liddle's based on clinical features and lab findings.

**Core Concept**
Hypokalemic hypertension occurs due to activation of the renin-angiotensin-aldosterone system (RAAS) from volume depletion or renal tubular disorders. Gitelman syndrome, a genetic defect in the distal convoluted tubule, causes hypokalemia, hypomagnesemia, and metabolic alkalosis, with variable hypertension.

**Why the Correct Answer is Right**
Gitelman syndrome results from mutations in the *SLC12A3* gene, impairing the thiazide-sensitive Na-Cl cotransporter. This leads to excessive urinary loss of sodium, potassium, and magnesium. Volume depletion activates RAAS, increasing aldosterone and angiotensin II, which can elevate blood pressure in some patients. Hypokalemia occurs due to unopposed aldosterone effects on distal potassium excretion.

**Why Each Wrong Option is Incorrect**
**Option A:** Liddle’s syndrome causes hypertension and hypokalemia due to aldosterone-independent sodium retention but lacks hypomagnesemia and is unrelated to RAAS activation.
**Option B:** Cushing’s syndrome may cause hypokalemia from cortisol-induced aldosteronism but is associated with hyperglycemia, central obesity, and other features.
**Option D:** Bartter syndrome involves similar electrolyte losses but presents with more severe hypokalemia, normotension, and early-onset symptoms, differing

✓ Correct Answer: D. Liddle syndrome