Polycystic kidney disease (PKD) is an inherited disorder (with autosomal dominant inheritance -- if one parent carries the gene, the children have a 50% chance of developing the disorder) where multiple clusters of cysts form on the kidneys. The exact mechanism that triggers cyst formation is unknown. PKD is associated with brain aneurysms,diverticula of the colon, and with cysts in the liver, pancreas, and testes. As many as half of people with PKD also have cysts on the liver. In early stages of the disease, the cysts enlarge the kidney and interfere with kidney function, resulting in chronic high blood pressure and kidney infections. The cysts may cause the kidneys to increase production of erythropoietin (the hormone that stimulates production of red blood cells) resulting in too many red blood cells, rather than the expected anemia of chronic kidney disease. Bleeding in a cyst can cause flank pain. Kidney stones are more common in people with PKD. Hypertension (high blood pressure) caused by polycystic kidneys may be difficult to control. The disease gets worse slowly, eventually resulting in end-stage kidney failure. It is also associated with liver disease, including infection of liver cysts. An autosomal recessive form of polycystic kidney disease also exists and appears in infancy or childhood; it tends to be very serious and progresses rapidly, resulting in end-stage kidney failure and generally causing death in infancy or childhood. Autosomal dominant PKD occurs in both children and adults, but it is much more common in adults, with symptoms often not showing up until middle age. It affects nearly 1 in 1,000 Americans. The actual number may be more, as some people do not have symptoms. The disorder may not be discovered unless tests revealing the disease are performed for other reasons. Risks include a personal or family history of polycystic kidney disease.
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