Calcium and Parathyroid USMLE Step 1 Practice Question
A 40-year-old woman undergoing genetic screening is found to have asymptomatic hypercalcemia (10.8 mg/dL) with suppressed PTH (18 pg/mL). She reports no polyuria or nephrolithiasis. Vital signs are normal (BP 120/80, HR 72, RR 16, Temp 37°C). Laboratory studies show normal renal function (creatinine 0.9 mg/dL), low urinary calcium-to-creatinine ratio (0.008), and normal 1,25-dihydroxyvitamin D. Family history reveals multiple relatives with asymptomatic hypercalcemia. Which diagnosis best explains these findings?
Answer choices
- AFamilial hypocalciuric hypercalcemiaCorrect answer
- BMalignancy-associated hypercalcemia
- CHyperthyroidism-induced osteoclasis
- DGranulomatous disease
- EPrimary hyperparathyroidism
- FVitamin A intoxication
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