Polycystic Kidney Disease

Polycystic kidney disease (PKD or PCKD, also known as polycystic kidney syndrome) is a cystic genetic disorder of the kidneys. There are two types of PKD: autosomal dominant polycystic kidney disease (ADPKD) and the less-common autosomal recessive polycystic kidney disease (ARPKD).

It occurs in humans and some other animals. PKD is characterized by the presence of multiple cysts (hence, "polycystic") typically in both kidneys; however 17% of cases initially present with observable disease in one kidney, with most cases progressing to bilateral disease in adulthood. The cysts are numerous and are fluid-filled, resulting in massive enlargement of the kidneys. The disease can also damage the liver, pancreas and, in some rare cases, the heart and brain. The two major forms of polycystic kidney disease are distinguished by their patterns of inheritance.

Polycystic kidney disease is one of the most common life-threatening genetic diseases, affecting an estimated 12.5 million people worldwide. In half of the people with polycystic kidney disease, there is no family history of the disease. In these cases, the gene coding for the disease occurs out of a spontaneous genetic mutation without either parent being a carrier of the gene.[citation needed]