Polycystic kidney disease (PKD)
DEFINITION
Polycystic kidney disease (PKD) is an inherited disorder in which clusters of cysts develop primarily within your kidneys. Cysts are noncancerous round sacs containing water-like fluid. The cysts vary in size and, as they accumulate more fluid, they can grow very large.
Although kidneys usually are the most severely affected organs, polycystic kidney disease can cause cysts to develop in your liver and elsewhere in your body. The disease causes a variety of serious complications.
A common complication of polycystic kidney disease is high blood pressure. Kidney failure is another common problem for people with polycystic kidney disease.
Polycystic kidney disease varies greatly in its severity, and some complications are preventable. Lifestyle changes and medical treatments may help reduce damage to your kidneys from complications, such as high blood pressure.
CAUSES
Abnormal genes cause polycystic kidney disease, and the genetic defects mean the disease runs in families. Rarely, a genetic mutation can be the cause of polycystic kidney disease.
There are two types of polycystic kidney disease, caused by different genetic flaws:
- 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 in order for it to pass along to the children. If one parent has ADPKD, each child has a 50 percent chance of getting the disease. This form accounts for about 90 percent of 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 percent chance of getting the disease.
Researchers have identified two genes associated with ADPKD and one associated with ARPKD.
In some cases, a person with ADPKD has no known family history of the disease. However, it’s possible that someone in the affected person’s family actually did have the disease, but didn’t show signs or symptoms before dying of other causes.
In a smaller percentage of cases where no family history is present, ADPKD results from a spontaneous gene mutation.
SYMPTOMS
Polycystic kidney disease symptoms may include:
- High blood pressure
- Back or side pain
- Headache
- Increase in the size of your abdomen
- Blood in your urine
- Frequent urination
- Kidney stones
- Kidney failure
- Urinary tract or kidney infections
When to see a doctor
It’s not uncommon for people to have polycystic kidney disease for years without developing signs or symptoms and without knowing they have the disease.
If you have some of the signs and symptoms of polycystic kidney disease, see your doctor to determine what might be causing them. If you have a first-degree relative — parent, sibling or child — with polycystic kidney disease, see your doctor to discuss the pros and cons of screening for this disorder.
