Doctors used to call autosomal dominant polycystic kidney disease (ADPKD) polycystic kidney disease in adults. That’s because children who carry one of two genes that cause it don’t usually feel sick. But ADPKD is a dominant genetic disease. Unlike many other disorders, ADPKD requires only one faulty copy of a gene.
This means that for every child of a parent with the condition, the chance of APDKD is about as high as tossing a coin. A genetic test could give you the answer from birth or even before. But there’s a lot an early genetic test can’t tell you. That’s because ADPKD symptoms can vary widely, even within the same family. In either case, the worst symptoms don’t show up until much later in life.
“For the kids, it often feels a lot less bad,” says Charlotte Gimpel, MD, a pediatric nephrologist at the University of Freiburg Medical Center in Germany. “Adults get huge kidneys and can be in a lot of pain until eventually their kidneys fail and they need dialysis. It is a serious illness for adults. Children used to be said to be asymptomatic.”
However, Gimpel says the notion that children with ADPKD have no symptoms is not “actually true”. Some children already have pain in their sides or back. You may have urinary tract infections (UTIs), kidney stones, or blood in your urine from cysts that have already formed in your kidneys. Gimpel says children may have trouble staying dry through the night if their kidneys aren’t working as well as they should.
“More children than we previously thought are getting high blood pressure or proteinuria” (extra protein in the urine that’s an early sign of kidney damage), she says, “It doesn’t feel like you’re sick, but you can treat.”
As doctors began to recognize these early signs of ADPKD, they began changing the way they treat children who may have the condition. “It used to be ‘hands off’ and don’t bother them with thinking about what you could have until they’re grown up and can decide for themselves,” says Gimpel.
There is no treatment to stop the cysts or future kidney problems. A drug to treat ADPKD is now approved for adults, but there is still no way to treat ADPKD in children. But doctors can help in other ways.
“If you leave them completely alone, you’re missing out on the 20% who have a treatable condition,” says Gimpel. “You can’t really cure a cystic disease, but treating high blood pressure is important to slow its progression [of kidney problems].”
ADPKD also affects other parts of the body. Adults can have problems in the liver, pancreas, intestines, and heart. But, Gimpel says, there’s no evidence these problems appear early in life, and children don’t need additional screening.
You don’t have to be sure if a child has ADPKD to tackle early signs as soon as they appear, Gimpel says.
To make sure you don’t miss out on those who could use early treatment, it’s so easy to keep an eye on blood pressure. That’s key, Gimpel says, because feelings about testing children vary widely in families affected by ADPKD across generations.
“Parents feel differently,” says Gimpel. “Some prefer not to know and want to keep it in the back of their minds. Others really want to know. If parents and child really want to know before a child is 18, it may be okay to do genetic testing.”
But there is no cure for ADPKD and no way to treat it in children. Experts believe that early intervention can help, but data on this is lacking.
“The consensus is: we do not recommend screening [kids for ADPKD] because there is no treatment to stop its progression,” says Christian Hanna, MD, a pediatric nephrologist at the Mayo Clinic. “There is no FDA-approved treatment. There is no clear evidence for this discovery [of ADPKD] in children without symptoms, outcomes will improve.”
That’s not to say nothing can be done, says Hanna. Children with ADPKD or at high risk can benefit from early education about healthy lifestyles. It’s a good idea for them to avoid salty foods and drink plenty of water. Exercise helps, but if a child already has kidney pain or cysts, it’s best to avoid contact sports like soccer or lacrosse.
Don’t overlook the challenges facing children’s mental health. Children may have seen their grandparents die of kidney problems, Gimpel says. You may see a parent with ADPKD living in pain. Whether or not a child has early signs, families need to think about how to talk to their children about ADPKD. Parents should inform children of their risks for ADPKD when they turn 18, if not earlier.
“When a child reaches adulthood without understanding their own health risks, she says, they often find it difficult to change how they think about the future.
“Talk to children in an age-appropriate way,” says Gimpel. “Don’t load them with too many facts. It’s good to start talking [early] about the uncertainty of not knowing if they have it and how to proceed.”