Causes

Abnormal genes cause polycystic kidney disease, which means that in most cases, the disease runs in families. Sometimes, a genetic mutation occurs on its own (spontaneous), so that neither parent has a copy of the mutated gene.

The two main types of polycystic kidney disease, caused by different genetic flaws, are:

• Autosomal dominant polycystic kidney disease (ADPKD). Signs and symptoms of ADPKD often develop between the ages of 30 and 40. In the past, this type was called adult polycystic kidney disease, but children can develop the disorder.

  Only one parent needs to have the disease for it to pass to the children. If one parent has ADPKD, each child has a 50% chance of getting the disease. This form accounts for most of the cases of polycystic kidney disease.

• Autosomal recessive polycystic kidney disease (ARPKD). This type is far less common than is ADPKD. The signs and symptoms often appear shortly after birth. Sometimes, symptoms don't appear until later in childhood or during adolescence.

  Both parents must have abnormal genes to pass on this form of the disease. If both parents carry a gene for this disorder, each child has a 25% chance of getting the disease.