People with polycystic kidney disease (PKD) inherit a gene change, or mutation, that causes numerous fluid-filled cysts to form in their kidneys. These kidney cysts take up a lot of space, causing potentially life-threatening problems. Nearly half a million Americans have PKD, making it one of the most common inherited conditions.

From the community: “My two adult sons were diagnosed with PKD as children. (their biological father has PKD) Son #1, age 45 had few large cysts and is in kidney failure. Son #2, 41 had many small cysts. Does the size or amount of cysts indicate the progress of kidney failure? 7 Grandchildren, so far the eldest 19, had been diagnosed with PKD.” – Inspire member

What are kidney cysts?

Kidney cysts are quite common: As many as half of people over 50 have a few fluid-filled sacs in one kidney. These cysts are unlikely to cause kidney cancer or other problems. They’re usually harmless and don’t require treatment. 

But kidney cysts caused by PKD are different. Instead of one or two cysts, thousands of cysts develop in both kidneys. With so many cysts crowding them, the kidneys grow larger and can push against other organs. The cysts prevent the kidneys from doing their primary job: filtering toxins from your blood and removing this waste in urine. PKD is a type of chronic kidney disease (CKD) that damages your kidneys and affects how well they function. This kidney damage is permanent. 

How do you get polycystic kidney disease (PKD)?

PKD is an inherited condition. You inherit a gene change that causes the disease from one or both parents. Rarely, someone with no known family history of PKD has a spontaneous (de novo) mutation that causes the disease. PKD affects people of all ages, genders, races, and ethnicities. 

There are two types of PKD: autosomal dominant polycystic kidney disease (ADPKD) and autosomal recessive polycystic kidney disease (ARPKD). ADPKD is the most common type of PKD. It affects as many as 1 in 400 to 1 in 1,000 people. In comparison, about 1 in 20,000 children develop ARPKD.

From the community: “Polycystic Kidney Disease is a genetic disorder, if you have the familial PKD history, you will have a greater chance to get it. If not, it may be simple renal cysts or multiple kidney cysts. both of them is easier to handle than PKD. do you get your medical report now? if you are diagnosed with PKD, it is necessary for your children to make an untrasound tests. Hope everything is fine.” – Inspire member

What’s the difference between ADPKD and ARPKD?

ADPKD and ARPKD cause multiple kidney cysts that damage the kidneys and eventually lead to kidney failure. Key differences between these conditions include:

• PKD gene mutation and trait

• PKD symptoms

• PKD treatments

• disease progression and prognosis

PKD gene mutation and trait

A different gene mutation causes each PKD type. The genes for the disease reside on different numbered chromosomes called autosomes. The way you inherit the changed gene (gene trait) is also unique. 

• Autosomal dominant or ADPKD: With an autosomal dominant disease like ADPKD, you only need to inherit a gene mutation from one parent to develop the disease. When a parent has the changed gene, a child’s odds of getting it are 50%. For ADPKD, a person may inherit a changed PKD1 gene on chromosome 16 or a changed PKD2 gene on chromosome 4. The mutated gene is the dominant gene, which means you are certain to develop ADPKD. You can’t be a carrier (someone who has the gene mutation but doesn’t develop the disease). Dominant diseases can affect all future generations.

• Autosomal recessive or ARPKD: In order to develop an autosomal recessive disease, a child must inherit two copies of a changed gene — one from each parent. With ARPKD, the parents are carriers of a changed PKHD1 gene on chromosome 6. As carriers, they don’t become sick with the illness. But there’s a 1 in 4 chance that each of their children will get the kidney disease. When only one parent has the gene change that causes ARPKD, their children can be carriers who pass the gene mutation to future generations. 

PKD symptoms

Doctors often use the term infantile PKD to refer to ARPKD because symptoms are evident soon after birth. In some instances, a prenatal ultrasound can detect signs of ARPKD like enlarged kidneys or low levels of amniotic fluid while a baby is still in the womb. 

Other signs of ARPKD or infantile PKD include:

• breathing problems 

• enlarged kidneys and spleen

• excessive urination

• high blood pressure

• liver cysts and scarring (fibrosis)

• low birth weight, small size, or failure to grow

• low blood count

People with ADPKD have the gene mutation that causes the disease at birth. However, ADPKD symptoms don’t typically appear until you’re in your 30s or older, when the cysts grow to about half an inch in size or larger. It’s commonly called adult PKD, although children occasionally have this type. 

Signs of ADPKD or adult PKD include:

• abdominal, back, or side pain or heaviness (kidney pain)

• blood in your urine (hematuria)

• high blood pressure

• kidney stones

• urinary tract infections (UTIs)

From the community: “I have PKD. It was 30 years from my diagnosis to dialysis. I never had any symptoms from the disease. Maybe some people do though. Are your kidneys enlarged? Enlargement is a big problem for some. My kidneys have lots and lots of cysts. Not just a few. Maybe I had a few in the beginning though. Your nephrology department can diagnose the problem. Take care, and, try not to worry?” – Inspire member 

PKD treatments

Treatments for PKD vary depending on the disease type and a person’s unique symptoms. 

Treatments for children with ARPKD include:

• mechanical ventilation to treat breathing problems due to enlarged kidneys pressing against the lungs

• medications to treat high blood pressure

• nutritional therapy and human growth hormone to help a child grow

• surgical removal (nephrectomy) of a kidney to aid breathing (or sometimes both kidneys)

• peritoneal dialysis using the child’s abdominal cavity and a cleansing solution to remove toxins from the body 

• kidney and liver transplant

ADPKD treatments include:

• an oral medicine that slows the growth of cysts, improving kidney function 

• antibiotics for bladder infections, kidney infections, and urinary tract infections (UTIs) 

• blood pressure medications

• pain relievers like acetaminophen or aspirin to ease discomfort caused by enlarged cysts (nonsteroidal anti-inflammatory drugs or NSAIDs can harm the kidneys)

• surgery to drain or remove an enlarged kidney cyst

• dialysis (treatment to filter wastes from blood) or a kidney transplant

Disease progression and prognosis

ADPKD and ARPKD are progressive chronic kidney diseases that are the fourth leading cause of kidney failure. When you have kidney failure, your kidneys only function at about 10% of their ability. Toxins start to build up in your blood, and you need medical interventions to stay alive.

Approximately 1 in 3 children with ARPKD will develop kidney failure and need dialysis or a kidney transplant by age 10. The disease can also affect the liver, causing a condition called congenital hepatic fibrosis. This condition leads to liver cysts, and an enlarged liver and spleen. Many kids with ARPKD will also need a liver transplant. With proper medical care, 9 out of 10 kids with ARPKD live to at least age 20. And half of them never need dialysis or an organ transplant.

More than half of people with ADPKD develop kidney failure that requires dialysis or a kidney transplant by age 50. As the disease progresses, adults with ADPKD may develop complications like:

• aneurysm (weakened bulge in an artery wall that can leak blood or rupture)

• liver cysts 

• mitral valve prolapse (a heart valve that doesn’t close properly) 

Sources

• Kidney failure (ESRD) causes, symptoms, and treatments. American Kidney Fund.

• Polycystic kidney disease (PKD) symptoms, treatments, and causes. American Kidney Fund.

• Autosomal dominant polycystic kidney disease (ADPKD). American Kidney Fund. 

• Kidney cysts. Cleveland Clinic. January 2021.

• Kidney disease/chronic kidney disease. Cleveland Clinic. December 2020.

• Polycystic kidney disease. Mayo Clinic. September 2020.

• Autosomal dominant. MedlinePlus. January 2020.

• Autosomal recessive. MedlinePlus. January 2020.

• Polycystic kidney disease. MedlinePlus. August 2020.

• Autosomal dominant polycystic kidney disease National Institute of Diabetes and Digestive and Kidney Diseases. January 2017.

• Autosomal recessive polycystic kidney disease National Institute of Diabetes and Digestive and Kidney Diseases. January 2017.

• What is polycystic kidney disease? National Institute of Diabetes and Digestive and Kidney Diseases. January 2017.

• What is kidney failure? National Kidney Foundation. 

• What causes ADPKD? PKD Foundation. June 2021.

• What causes ARPKD? PKD Foundation. June 2021.

• What is ADPKD? PKD Foundation. June 2021.

• What is ARPKD? PKD Foundation. July 2021.

Disclaimer

Member comments are lightly edited for length and to remove identifying information but are otherwise reproduced as they appear in the community as part of public posts.

This content is for general informational purposes only and does not necessarily reflect the views and opinions of any organization or individual. The content should not be used as a substitute for professional medical advice, diagnosis, or treatment. Please consult your healthcare provider about any questions you may have regarding a medical condition.