Free nephrology board questions: Genetic GN

A 35-year-old woman with ADPKD has no personal history of subarachnoid hemorrhage (SAH). Her older sister was found to have an unruptured intracranial aneurysm (ICA) on incidental imaging. She requests guidance on ICA screening. Per KDIGO 2025, does she qualify for ICA screening, and what is the preferred imaging modality?

A 36-year-old man with ADPKD (PKD1 mutation confirmed) has eGFR 72 mL/min and total kidney volume (TKV) of 2,100 mL (adjusted for height: htTKV 1,350 mL/m, Mayo Imaging Class 1D). He has no prior liver cysts and no hyponatremia. He drinks 2L of water daily. His physician considers tolvaptan. Which statement best describes the evidence and patient selection for tolvaptan in ADPKD?

A 23-year-old man is referred for evaluation of CKD. During a life insurance evaluation 4 months ago, a serum creatinine of 1.7 mg/dL was found. The patient has no significant medical history, and he was born at term. He takes no prescribed or over-the-counter medications, including NSAIDs, herbal products, or illicit drugs. The patient's mother is well. His father died in a motor vehicle accident at age 26. Both the patient and his 20-year-old sister have had nocturia since childhood. Review of systems is otherwise negative. On examination, BP is 110/70 mm Hg, heart rate is 64/min, and body mass index is 24 kg/m². Pupils, fundi, and visual acuity are grossly normal. Hearing is grossly intact to whispered speech. Heart, lung, and abdominal examinations are normal, and there is no edema or rash. Laboratory data: sodium 142 mEq/L (reference 136–145); potassium 4.0 mEq/L (3.5–5.0); total CO₂ 23 mEq/L (23–28); creatinine 1.8 mg/dL (0.7–1.3); calcium 9.5 mg/dL (8.6–10.2); phosphorus 3.4 mg/dL (3.0–4.5); albumin 4.2 g/dL (3.5–5.5); urine albumin-to-creatinine ratio 42 mg/g (<30). Urinalysis reveals specific gravity 1.010, trace albumin, and no blood. Microscopy is unremarkable. Kidney ultrasound shows normal-sized kidneys with mildly increased echogenicity. Which of the following tests would be MOST LIKELY to yield a diagnosis?