Polycystic kidney disease (PKD) is a genetic disorder characterized
by the growth of numerous cysts in the kidneys. PKD cysts can profoundly
enlarge the kidneys while replacing much of the normal structure,
resulting in reduced kidney function and leading to kidney failure.
When PKD causes kidneys to fail—which usually happens after
many years—the patient requires dialysis or kidney transplantation.
About one-half of people with the most common type of PKD progress
to kidney failure, also called end-stage renal disease (ESRD). PKD
can also cause cysts in the liver and problems in other organs,
such as blood vessels in the brain and heart. The number of cysts
as well as the complications they cause help doctors distinguish
PKD from the usually harmless “simple” cysts that often
form in the kidneys in later years of life. In the United States,
about 600,0001 people have PKD, and cystic disease is the fourth
leading cause of kidney failure. A genetic test can detect mutations
in the autosomal dominant PKD genes, called PKD1 and PKD2.