DefinitionPolycystic kidney disease is a kidney disorder passed down through families in which multiple cysts form on the kidneys, causing them to become enlarged.Alternative NamesCysts - kidneys; Kidney - polycystic; Autosomal dominant polycystic kidney disease; ADPKDCauses, incidence, and risk factorsPolycystic kidney disease (PKD) is passed down through families (inherited), usually as an autosomal dominant trait. If one parent carries the gene, the children have a 50% chance of developing the disorder.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 discove