Polycystic Kidney Disease – Autosomal Dominant (ADPKD) (Stud…
Polycystic Kidney Disease – Autosomal Dominant (ADPKD) (Study Outline) 1. Background Definition: A genetic disorder causing progressive formation and enlargement of numerous kidney cysts → renal enlargement, loss of function, and eventual CKD/ESRD. Genetics: Autosomal dominant inheritance. Mutations in PKD1 (≈85%) or PKD2 (≈15%); PKD1 associated with earlier, more severe disease. Pathophysiology: Cyst formation from renal tubules → expansion → compression of normal parenchyma → ischemia and fibrosis. Epidemiology: Most common life-threatening monogenic kidney disorder. Presents in adulthood (often ages 20–40). Associated extrarenal manifestations: Hepatic cysts (most common). Pancreatic and splenic cysts. Cerebral aneurysms (berry aneurysms). Cardiac valve abnormalities (MVP, AR). Diverticulosis, abdominal wall/inguinal hernias. 2. History Flank or abdominal pain: due to cyst enlargement, bleeding, or infection. Hematuria: microscopic or gross; often from cyst rupture. Hypertension: very common early due to RAAS activation. Recurrent UTIs or pyelonephritis. Nephrolithiasis (uric acid or calcium oxalate). Family history: first-degree relatives frequently affected. Progressive symptoms of CKD later (fatigue, nocturia, edema). 3. Exam Findings Abdominal masses: bilateral, palpable enlarged kidneys (important exam clue). Hypertension (often severe). Signs of CKD: edema, pallor, asterixis (later stages). Liver enlargement if significant hepatic cysts. Neurologic red flags: severe headaches (possible aneurysm). 4. Making the Diagnosis Labs: Proteinuria (usually mild), possible hematuria. Progressive elevation in BUN/Cr with disease advancement. Imaging (high-yield): Ultrasound = first-line test Shows multiple bilateral renal cysts of varying sizes. CT/MRI: used if ultrasound inconclusive. Diagnostic criteria (age-based, classic): ≥3 cysts total (unilateral or bilateral) if age