Polycystic kidney disease (PKD) is a genetic disease of the kidneys in which there are dilations of all parts of the nephron, the main filtering mechanism. The nephron, composed of glomeruli (singular, glomerulus)–a tuft of capillaries surrounding a collecting tubule, is the interface where waste products are filtered and collected as urine.
PKD is due to a dominant gene, with a 50% chance of passing it down to one’s offspring. There is a much rarer recessive gene, seen mostly in children, fifty times less frequent than the dominant version.
PKD causes increased kidney size, as much as 5 times normal, due to microcysts, with progressively larger cysts causing a decrease in renal function. Nephrectomy–removal of the kidney–is indicated when there are recurrent infections, incapacitating pain, renal cell carcinoma, or hematuria requiring repetitive transfusions. When the severity of kidney dysfunction reaches end-stage renal disease (ESRD), either dialysis or kidney transplant is necessary.
Signs and Symptoms
- Hematuria: visibly blood-tinged urine
- Decrease in concentration of urine
- Proteinuria: Release of protein from the blood into the urine, which increases with PKD severity
- Kidney stones: primarily of uric acid. (Most stones in non-PKD patients are calcium oxalate)
- Pain: flank or abdominal, from infections, kidney stones, or cyst hemorrhage
- Higher risk of kidney cancer (renal cell carcinoma)