By: Darcy Weidemann, MD, MHS, FAAP & Laura Malaga-Dieguez, MD, PhD, FAAP
Autosomal recessive polycystic kidney disease (ARPKD) is a rare but serious genetic condition that affects the development of the kidneys and liver. The kidneys develop fluid-filled sacs (called cysts), leading to enlarged kidneys. The liver can develop scar tissue. Over time, either one or both organs may stop working properly.
What causes ARPKD?
ARPKD is caused by mutations (changes) in the PKDH1 gene that’s passed along in families. It is estimated to affect about 1 in 20,000 babies. Girls and boys are equally affected.
"Autosomal recessive" means that for a child to have ARPKD both parents must have one of the mutated genes and pass it along to the child. There is a 1 in 4 chance that their child will be affected by ARPKD. The child will then be a "carrier," just like both parents.
How is ARPKD diagnosed?
ARPKD is most often diagnosed early in life. Many babies are diagnosed before birth during pregnancy or shortly after they are born. In some cases, the disease is milder and may not be found until early childhood or the teenage years, often after genetic testing is done.
Prenatal genetic testing & ultrasound imaging
Prenatal genetic testing is available using samples from the placenta lining the uterus or the amniotic fluid that surrounds the fetus This is usually done when the parents have had a previous child with ARPKD.
Prenatal ultrasounds can also be used to diagnose ARPKD. Babies with the most severe form of ARPKD often cannot survive very long outside of the womb because their lungs did not develop normally due to the low levels of amniotic fluid. About 20% of babies with ARPKD do not survive the newborn period.
Diagnosis after the newborn period
All patients with ARPKD have kidney cysts. However, the size, number, and severity of cyst formation can be very different from person to person. Children who survive the newborn period usually develop worsening kidney function over time.
Children may be diagnosed with ARPKD after infancy when high blood pressure, enlarged kidneys, or symptoms from decreased kidney function are noted by a physician.
What are the signs and symptoms of ARPKD?
Symptoms of ARPKD include:
Difficulties breathing
High blood pressure (hypertension)
Excessive thirst (polydipsia)
Excessive urination (polyuria)
Loss of kidney function over time, also called chronic kidney disease (CKD)
Side or flank pain
Weakness or fatigue
Puffiness or swelling
Poor appetite and/or poor growth
Scarring of the liver (congenital hepatic fibrosis)
When should I call the doctor?
Be sure to contact the doctor if your child is experiencing:
How is ARPKD treated?
There is no cure for ARPKD, and most patients require treatment for different signs and symptoms of the kidney and liver disease associated with ARPKD. Most of the health problems children experience are caused by chronic kidney disease (CKD) that develops because the kidneys do not form or work normally.
Kidney enlargement cannot be prevented. Sometimes, one or both kidneys may need to be removed if their size makes breathing too difficult.
Infants with breathing problems may be treated with an artificial ventilation machine to help them breathe. High blood pressure may be treated with medications or a low salt diet may also be needed.
Chronic kidney disease may be managed with medications called ACE inhibitors which help protect kidney function and slow further damage. Diet changes may also be needed to reduce stress on the kidneys.
Poor growth may occur due to reduced appetite, poor nutrition and hormone imbalances caused by CKD. This can be treated with nutritional support and, in some cases, growth hormone injections.
Anemia (low red blood cell count) is common in children with CKD because damaged kidneys do not make enough erythropoietin, a hormone that helps produce red blood cells. Treatment may include iron supplements or erythropoietin injections.
When kidney function becomes severely reduced, some children may need dialysis, a treatment that removes waste and extra fluid from the blood. Others may eventually require a kidney transplant, which can significantly improve quality of life and overall health.
Special concerns for children with ARPKD
Many children with ARPKD will have difficulty concentrating their urine. As a result they may pee more frequently than children with normal kidneys, and oftentimes continue to wet the bed at night. Because of frequent urination, children with ARPKD should always have easy access to liquids to prevent dehydration.
Children with ARPKD may be advised to avoid contact sports, as enlarged kidneys are more vulnerable to injury, which could cause serious bleeding or pain.
Your doctor may also advise avoiding certain over-the-counter medications such as non-steroidal anti-inflammatory medications (NSAIDS such as ibuprofen) which can be harmful to the kidneys.
What are possible long-term effects of ARPKD?
The long-term prognosis for children with ARPKD has improved over the past several decades. Twenty years ago, only half of the children with ARPKD survived to their 10th birthday. Now, more than 90% of children who survive the newborn period live to their 20th birthday and only around half of these children require dialysis or transplantation.
Most children with ARPKD will eventually develop kidney failure sometime in their life. The only treatments for kidney failure are kidney transplantation or dialysis. Some patients with severe liver disease may need a liver transplant. Some children will receive a kidney transplant at the same time as a liver transplant.
More Information
About Dr. Malaga-Dieguez, MD, PhD
Laura Malaga-Dieguez, MD, PhD, FAAP, is the Division Director of Pediatric Nephrology and Medical Director of the Pediatric Kidney Transplant Program at Hassenfeld Children’s Hospital at NYU Langone in New York City, NY. She is involved in clinical trials and research studies trying to understand why children develop certain types of kidney disease (glomerular disease), and in medical education, serving as director of the Nephrology course at NYU Grossman School of Medicine.
About Dr. Weidemann
Darcy Weidemann, MD, MHS, FAAP, is a pediatric nephrologist who practices at Children’s Mercy Hospital in Kansas City, Missouri. She completed her medical training in 2009 at Johns Hopkins School of Medicine. She remained in Baltimore for the duration of her training, completing her pediatrics residency at Johns Hopkins Children’s Center in 2012 and pediatric nephrology fellowship training in 2015. She also received a master’s degree in clinical epidemiology through the Bloomberg School of Public Health in 2014. Within the American Academy of Pediatrics, she is a member of the Section on Nephrology.