Diabetes Mellitus USMLE Step 1 Practice Question
A 28-year-old man presents with recurrent nephrolithiasis and refractory peptic ulcer disease. Vital signs are stable (BP 128/82, HR 88, RR 16, Temp 37°C). Laboratory studies reveal hypercalcemia (10.8 mg/dL), elevated fasting gastrin (450 pg/mL), and normal glucose (95 mg/dL). Serum PTH is elevated. MRI brain demonstrates a 1.2-cm pituitary lesion. He denies thyroid symptoms. Which gene is most likely mutated in this patient?
Answer choices
- ATP53 tumor suppressor gene
- BNF1 tumor suppressor gene
- CMEN1 tumor suppressor gene encoding meninCorrect answer
- DVHL tumor suppressor gene
- ERET proto-oncogene
- FCDKN1B tumor suppressor gene encoding p27
See the full explanation
Get the correct-answer rationale, why each distractor is wrong, the underlying mechanism, and high-yield associations — plus adaptive practice that targets your weak areas — with a free MedBoardPRO account.