What are the genetic changes related to polycystic kidney disease ?
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 2. These genes provide instructions for making proteins whose functions are not fully understood. Researchers believe that they are involved in transmitting chemical signals from outside the cell to the cell's nucleus. The two proteins work together to promote normal kidney development, organization, and function. Mutations in the PKD1 or PKD2 gene lead to the formation of thousands of cysts, which disrupt the normal functions of the kidneys and other organs. People with mutations in the PKD2 gene, particularly women, typically have a less severe form of the disease than people with PKD1 mutations. The signs and symptoms, including a decline in kidney function, tend to appear later in adulthood in people with a PKD2 mutation.  Mutations in the PKHD1 gene cause autosomal recessive polycystic kidney disease. This gene provides instructions for making a protein whose exact function is unknown; however, the protein likely transmits chemical signals from outside the cell to the cell nucleus. Researchers have not determined how mutations in the PKHD1 gene lead to the formation of numerous cysts characteristic of polycystic kidney disease.  Although polycystic kidney disease is usually a genetic disorder, a small percentage of cases are not caused by gene mutations. These cases are called acquired polycystic kidney disease. This form of the disorder occurs most often in people with other types of kidney disease who have been treated for several years with hemodialysis (a procedure that filters waste products from the blood).