What Is Autosomal Dominant Polycystic Kidney Disease?
Autosomal dominant polycystic kidney disease (ADPKD) causes a lot of fluid-filled sacs, called cysts, to grow in your kidneys. The cysts keep your kidneys from working like they should. That can cause health problems like high blood pressure, infections, and kidney stones. It can also cause kidney failure, although that doesn't happen to everyone.
You can have ADPKD and not know it for many years. It’s often called “adult PKD,” because the symptoms don't usually appear until people reach ages 30 to 40. But over time, ADPKD can start to damage your kidneys.
You can slow the damage and prevent some of the complications by making healthy habits -- especially those that help you lower and then maintain your blood pressure -- part of your life and taking medications as necessary. Depending on the type of ADPKD you have, you can lead an active life for many years by managing your symptoms and working with your doctor. There’s no cure, but scientists are doing research to look for new treatments.
ADPKD is caused by a problem with one of two genes in your DNA -- PKD1 or PKD2. These genes make proteins in kidney cells that let them know when to grow. A problem with either gene may cause kidney cells to grow out of control and form cysts.
Many genetic diseases happen when a person gets broken genes from both parents, but with ADPKD you need only one faulty gene to have the disease. That's why this kind of PKD is called “autosomal dominant,” meaning only one parent has to pass on a broken gene.
If one parent has the disease, each child has a 50-50 chance of getting it.
You can get ADPKD even if neither of your parents had the disease. This happens when one of your PKD genes gets a defect on its own. But it’s rare for someone to get it this way.
Not everyone with ADPKD will have symptoms. Those who do may not notice anything for many years. Most people with the disease have high blood pressure. Urinary tract infections and kidney stones are also common.
Other signs that you have ADPKD include:
- Pain in your back or sides, often because of a burst cyst, a kidney stone, or a urinary tract infection
- Blood in your pee
- Swelling in your belly as the cysts grow
Over time, cysts may grow big enough to damage your kidneys, and for some people, can cause them to fail. If that happens, you may have:
Getting a Diagnosis
If your doctor thinks there’s a problem with your kidneys, she may want you to see a nephrologist, a specialist who treats kidney diseases. He’ll ask you questions, like:
- What kind of symptoms are you having? When did they start?
- How often do you feel that way?
- Do you know your blood pressure?
- Have you been having any pain? If so, where?
- Have you ever had kidney stones? How often do you get them?
- Has anyone in your family been diagnosed with kidney disease?
- Have you ever had a genetic test?
The doctor will do some tests to get images of your kidneys and check them for cysts. He may start with an ultrasound, which uses sound waves to make a picture of the inside of your body. To look for cysts that are too small for an ultrasound to find, he could also use:
- MRI. It uses powerful magnets and radio waves to make pictures of organs and structures inside your body.
- CT scan. It's a powerful X-ray that makes detailed pictures inside your body.
Doctors can also test your DNA to see if you have a broken PKD1 or PKD2 gene. But it’s important to know the limits of the test. It can show if you have the gene mutation, but it can't tell when you will first develop symptoms of ADPKD.
Questions to Ask Your Doctor
- How will this disease make me feel?
- Do I need any more tests?
- Do I need to see a specialist?
- What are my treatment options?
- Do the treatments have side effects?
- What do you expect for my case?
- What can I do to keep my kidneys working?
- If I have children, will they get the disease?
- Do my children need to get a genetic test?
There is no cure for ADPKD, but you can treat the health problems that the disease causes and possibly prevent kidney failure. You may need:
- Medicine to prevent kidney failure. Tolvaptan (Jynarque) can slow the decline of kidney function for adults whose disease is at risk of progressing rapidly.
- Medicines to lower your blood pressure
- Antibiotics to treat urinary tract infections
- Pain medicines
If your kidneys fail, you’ll need dialysis, which uses a machine to filter your blood and remove waste, like salt, extra water, and certain chemicals. You can also get on a waiting list or receive a kidney from a living donor for a kidney transplant. Ask your doctor if that’s a good option for you.
Taking Care of Yourself
It's important to stay as healthy as possible to protect your kidneys and keep them working as long as you can. Follow your doctor's advice carefully. You can also keep up these habits to stay well:
Eat right. Stick to a healthy, well-balanced diet. Try to limit salt, because it can raise your blood pressure.
Stay active. Exercise can help control your weight and blood pressure. Just avoid any contact sports where you might injure your kidneys.
Don't smoke. If you smoke, get help from your doctor to quit. Smoking damages the blood vessels in the kidneys, and it may create more cysts.
Drink plenty of water. Dehydration may cause you to have more cysts.
What to Expect
Cysts often grow very slowly. They can grow even slower when you control your blood pressure and make healthy lifestyle choices. But after many years, they can get large enough to damage your kidneys. As time goes on, some people get kidney failure and need dialysis or a kidney transplant.
How quickly the disease gets worse may depend on which of your two PKD genes is broken. People with a defect in the PKD1 gene tend to get kidney failure before those with a problem in PKD2.
ADPKD can also raise your risk for other health problems, such as:
- A bulge in a blood vessel of the brain, called an aneurysm
- Cysts on the liver and pancreas
- Heart valve diseases such as mitral valve prolapse and aortic regurgitation
For more information on ADPKD, visit the web site of the PKD Foundation.