Chronic Kidney Disease USMLE Step 1 Practice Question
A 17-year-old boy is referred for severe hypertension (BP 168/102 mmHg, HR 88, RR 16, temp 37°C) discovered during a sports physical. Laboratory studies reveal hypokalemia (K+ 2.8 mEq/L), metabolic alkalosis (HCO3− 32 mEq/L), and suppressed plasma renin activity with low aldosterone levels. Urine sodium is elevated at 180 mEq/day. He denies licorice use and takes no medications. Which of the following is the most likely cause?
Answer choices
- AConstitutive activation of epithelial sodium channels in principal cellsCorrect answer
- BExcess aldosterone secretion from an adrenal adenoma
- CHyposecretion of aldosterone due to diabetic nephropathy
- DDefective Na K 2Cl cotransporter in the thick ascending limb
- EReduced responsiveness to antidiuretic hormone
- FApparent mineralocorticoid excess from 11β-HSD2 deficiency
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