Nephrology

Polycystic kidney disease is a disorder that affects the kidneys and other organs. Clusters of fluid-filled sacs, called cysts, develop in the kidneys and interfere with their ability to filter waste products from the blood. The growth of cysts causes the kidneys to become enlarged and can lead to kidney failure.

The two major forms of polycystic kidney disease are distinguished by the usual age of onset and the pattern in which it is passed through families. The autosomal dominant form (sometimes called ADPKD) has signs and symptoms that typically begin in adulthood, although cysts in the kidney are often present from birth or childhood.  

 Polycystic kidney disease is a fairly common genetic disorder. It affects about 500,000 people in the United States. The autosomal dominant form of the disease is much more common than the autosomal recessive form. Autosomal dominant polycystic kidney disease affects 1 in 500 to 1,000 people, while the autosomal recessive type occurs in an estimated 1 in 20,000 to 40,000 people.

Mutations in the PKD1, PKD2, and PKHD1 genes cause polycystic kidney disease.

Mutations in either the PKD1 or PKD2 gene can cause autosomal dominant polycystic kidney disease; PKD1 gene mutations cause ADPKD type 1, and PKD2 gene mutations cause ADPKD type.

Most cases of polycystic kidney disease have an autosomal dominant pattern of inheritance. People with this condition are born with one mutated copy of the PKD1 or PKD2 gene in each cell. In about 90 percent of these cases, an affected person inherits the mutation from one affected parent. The other 10 percent of cases result from a new mutation in one of the genes and occur in people with no history of the disorder in their family. 

Kidney stones (also called renal stones or urinary stones) are small, hard deposits that form in one or both kidneys; the stones are made up of minerals or other compounds found in urine. Kidney stones vary in size, shape, and color. 

People are most likely to develop kidney stones between ages 40 and 60, though the stones can appear at any age. Research shows that 35 to 50 percent of people who have one kidney stone will develop additional stones, usually within 10 years of the first stone.

In the United States, 9 percent of women and 19 percent of men develop kidney stones in their lifetime.

Genetic changes can increase the risk of developing kidney stones, often acting in combination with a variety of environmental and lifestyle factors. Most genes involved in the condition are important for transmitting chemical signals from outside cells to inside cells or transporting materials in and out of cells. These processes help regulate the levels of various materials within cells, including the minerals and compounds that make up kidney stones.