Glomerular Diseases USMLE Step 1 Practice Question
A 32-year-old man presents with progressive bilateral sensorineural hearing loss and progressive vision changes. Laboratory evaluation reveals persistent hematuria, proteinuria of 1.8 g/day, and serum creatinine of 1.6 mg/dL. Vital signs are stable (BP 138/88 mmHg, HR 82, RR 16, Temp 37°C, SpO2 98%). Kidney ultrasound shows normal-sized kidneys without hydronephrosis. Kidney biopsy demonstrates IgA-negative glomerulonephritis with characteristic GBM splitting and "basket-weave" appearance on electron microscopy. Which genetic mutation is most likely responsible?
Answer choices
- ACFHR5 (complement factor)
- BCOL4A3 or COL4A4 (type IV collagen)Correct answer
- CCD103 (integrin-alpha)
- DTP53 (tumor suppressor)
- ENPHS1 (nephrin)
- FSLC12A3 (sodium-chloride cotransporter)
See the full explanation
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