Overview
Definition
A multisystemic and progressive genetic disorder characterized by the formation and enlargement of multiple cysts in the kidneys and other organs.
Epidemiology
The most common inherited kidney disease (1 in 400-1000). Usually presents in the 30s or 40s.
Etiology & Risk Factors
- Mutation in PKD1 (chromosome 16, 85% of cases, more severe) or PKD2 (chromosome 4, 15% of cases)
- Cysts gradually enlarge, compressing and destroying normal renal parenchyma.
Clinical Symptoms
- Flank or back pain (due to cyst enlargement or hemorrhage)
- Gross hematuria
- Early-onset, difficult-to-control Hypertension
- Palpable bilateral abdominal masses
Clinical Approach
Diagnosis
- Renal Ultrasound (Diagnostic test of choice): Innumerable bilateral renal cysts and massive kidney enlargement
- Genetic testing (if imaging is equivocal in young patients)
Management
- Aggressive BP control (ACE inhibitors or ARBs are first-line)
- Tolvaptan (Vasopressin V2 receptor antagonist) can slow cyst growth and preserve renal function in high-risk patients
- Increased fluid intake (suppresses ADH which drives cyst growth)
- Management of ESRD (Dialysis or Renal Transplantation)
Complications
- End-Stage Renal Disease (by age 60 in half of patients)
- Berry Aneurysms (Subarachnoid Hemorrhage) - high association, screen with MR Angiography if family history is positive
- Hepatic cysts (very common)
- Mitral Valve Prolapse