Pulmonary hypertension (PH) is often linked with several other conditions, one of which is Down syndrome. Parents of children who are born with Down syndrome may need to be on the lookout for symptoms of PH, especially if their child has an underlying heart condition.

If you’re the parent or caretaker of a loved one with Down syndrome, here’s what you need to know about PH and pediatrics. This knowledge will help you recognize symptoms and ensure your loved one receives the necessary medical attention when required.

What Is Down Syndrome?

Down syndrome, or trisomy 21, is a chromosomal abnormality that occurs in 1 in 733 live births. This genetic condition happens when all or part of chromosome 21 gets copied three times, instead of the usual two — this is called trisomy.

This extra chromosome copy can cause several issues in the body in children with Down syndrome, from cognitive difficulties to heart problems, distinctive facial features (such as upward-slanting, almond-shaped eyes), alopecia (hair loss), an increased chance of certain kinds of cancers, and more. One of these issues is PH.

Are Pulmonary Hypertension and Down Syndrome Related?

People living with Down syndrome are more likely to develop PH than those in the general population. One collection of studies on the topic shows it occurs frequently, with about 25.5 percent of people with Down syndrome developing PH. In fact, the researchers noted that all children diagnosed with Down syndrome should be tested for PH because they may have it even if symptoms are not obvious right away and they don’t have another underlying heart problem.

On myPHteam, a few people have experienced the overlap between Down syndrome and PH. One said, “My daughter has Down syndrome. She had two heart surgeries, and she recently was diagnosed with PH.”

It’s unknown exactly why those with Down syndrome are more likely to experience PH. However, there are a few areas when having certain issues caused by Down syndrome can make someone more likely to also experience PH. A higher risk of PH does not seem to be associated with any medications given for issues related to Down syndrome.

Down Syndrome and Congenital Heart Disease

One possible explanation for the connection is that individuals with Down syndrome are more likely to experience certain heart problems. They are often born with congenital heart diseases (CHDs), which affect the way their heart works. Most of these require one or more surgeries while the child is still very small, typically between the ages of one and three.

In general, congenital heart diseases correlate with a certain type of PH, called pulmonary arterial hypertension (PAH). Thus, at least some of the cases of PH associated with Down syndrome are likely due to congenital heart defects.

Down Syndrome and Sleep Apnea

Having Down syndrome is also a risk factor for experiencing sleep apnea, which can cause PH. Approximately 30 percent to 50 percent of people diagnosed with Down syndrome will experience sleep apnea, as opposed to about 3 percent of the population without the syndrome. People with Down syndrome are specifically more likely to experience obstructive sleep apnea.

In this kind of sleep apnea, the muscles in the throat relax so much when the person sleeps that they block the flow of air when the person tries to breathe. This kind of blocking of the upper part of the airway (upper airway obstruction) is associated with a greater chance of PH.

Down Syndrome and Abnormal Lung Development

Some people with Down syndrome have lungs that develop differently from those without the condition. Sometimes, the blood vessels in the lungs are wider than normal, while other times they are narrower. The arteries in the lungs might be located in different spots or have a unique structure. When you examine the very smallest details of the respiratory system in a person with Down syndrome, you may notice that their lungs have unique characteristics or work differently compared to the lungs of individuals who do not have Down syndrome.

All of these variations can add stress to the cardiovascular system and blood flow, which may result in PH. It is difficult to know how frequently this occurs because some of these changes in the lungs can be hard to diagnose except through autopsy. For this reason, the cause behind some cases of PH in people with Down syndrome may be unclear while they’re alive.

Down Syndrome and Gastrointestinal Reflux

Gastrointestinal reflux, or acid reflux, is also more common in people with Down syndrome than in the rest of the population. While it’s unknown if this alone is enough to make a person likely to have PH, it does add to airway blockage, which can make PH worse. In fact, children who have been treated with reflux medications are somewhat more likely to also experience PH. Even though reflux may not cause PH, it does seem to make it worse. Additional research is needed to determine the relationship between these two diagnoses, particularly in those with Down syndrome.

PH Isn’t Typically Worse Among Those With Down Syndrome

Although people with Down syndrome are more likely to be diagnosed with PH, they may not be more likely to die from it, especially if they are diagnosed when they’re very young. Children who have both PH and Down syndrome are not at a greater risk of dying from PH compared to those who have PH alone. In other words, their chances of PH causing death are about the same.

Additionally, PH resolves itself at the same rates in children with and without Down syndrome. So, having Down syndrome makes it more likely that a person will experience PH and its associated prognosis (outlook), but it does not mean that the PH is more severe or has worse outcomes than it does in people without Down syndrome.

Talk to Your Doctor

If your child has been diagnosed with Down syndrome or if you’re the caregiver for a loved one living with this diagnosis, follow up with their doctor or cardiology team about PH. If they’ve been screened for it, you may end up with greater peace of mind. If they have not, you can advocate for testing just to make sure they are not living with PH.

If your loved one with Down syndrome has already been diagnosed with PH, it’s important to ensure they regularly visit their cardiologist and pulmonologist. This kind of ongoing monitoring helps you keep track of the condition and stay ahead of it. If you notice any changes, like increased shortness of breath or chest pain, it’s crucial to get them to a doctor promptly. Your medical team can work with you to find effective ways to manage your loved one’s PH and maintain a good quality of life and overall well-being.

Find Your Team

MyPHteam is the social network for people with pulmonary hypertension and their loved ones. On myPHteam, more than 51,000 members come together to ask questions, give advice, and share their stories with others who understand life with pulmonary hypertension.

Are you wondering about the connection between pulmonary hypertension and Down syndrome? Share your experience in the comments below, or start a conversation by posting on your Activities page.