Inheriting Polycystic Kidney Disease

Most cases of polycystic kidney disease are inherited in an autosomal dominant pattern, which means affected people may have affected siblings and relatives in successive generations (such as parents and children). In about 90 percent of these cases, an affected person inherits a mutation in the PKD1 or PKD2 gene from one affected parent. The other 10 percent of cases may result from new mutations in one of the genes. These cases occur in people with no history of the disorder in their family.

 

People with autosomal dominant polycystic kidney disease are born with one mutated copy of the PKD1 or PKD2 gene in each cell. Then, during their lifetime, a second mutation occurs in the other copy of the gene in kidney cells, or cells in other organs, triggering the cyst formation. The rate at which cysts enlarge and cause a loss of kidney function varies widely; it may be accelerated by a second mutation in PKD1 or PKD2, or by mutations in other important genes.

 

Polycystic kidney disease can also be inherited in an autosomal recessive pattern, which means that an affected person must inherit two altered copies of the PKHD1 gene to be affected by the disorder. Most often, the parents of a child with an autosomal recessive disorder are not affected, but are carriers of one copy of the altered gene.