Clinical meaning
Polycystic kidney disease (PKD) is a genetic condition where many fluid-filled cysts grow in both kidneys, gradually replacing normal tissue. As cysts grow over years, they destroy kidney structure and impair function, eventually leading to kidney failure.
The most common form is autosomal dominant PKD (ADPKD), meaning only one copy of the abnormal gene is needed. Symptoms usually appear in adulthood (ages 30-50), but cysts begin forming before birth. ADPKD affects approximately 1 in 400-1000 people.
As kidneys fill with cysts, they become very large. Patients may feel fullness or pain. Cysts can bleed, become infected, or develop stones. High blood pressure is very common and often appears before kidney function declines. About 50% of ADPKD patients develop kidney failure requiring dialysis or transplant by age 60.
Exam relevance
Risk factors: - Family history of PKD (autosomal dominant — 50% chance) - PKD1 mutation (more severe — ESRD average age 54) - PKD2 mutation (milder — ESRD average age 74) - Hypertension (accelerates damage) - Male sex (faster progression) - Frequent UTIs - Kidney stones - High-protein diet