Genetics and Aortic Disease: Why Family History Matters

When we think about aortic disease, things like blood pressure, age, and other health conditions often come to mind. But for some people, the health of the aorta can also be influenced by something they were born with: their genes.

Understanding the genetic side of aortic disease can help you learn more about your own risk and, in some cases, help protect other family members too.

How can genetics affect the aorta?

Our genes provide instructions for how our bodies grow and function. Some genes are involved in building and maintaining the connective tissue and smooth muscle that help make the wall of the aorta strong.

Changes in certain genes can make the aortic wall more likely to weaken, enlarge, or tear over time. When a genetic condition increases someone's risk for an aortic aneurysm or dissection, doctors may refer to it as a heritable thoracic aortic disease, or HTAD.

Importantly, having a genetic form of aortic disease does not mean that something will definitely happen to the aorta. It does mean that knowing about the risk can help a healthcare team decide how closely the aorta should be monitored.

Some genetic conditions that can affect the aorta include:

• Marfan syndrome

• Loeys-Dietz syndrome

• Vascular Ehlers-Danlos syndrome

  
  

There are also inherited forms of aortic disease that don't come with the more noticeable physical features of a genetic syndrome. Someone may look and feel completely healthy while still carrying a genetic change that increases their risk of developing an aortic aneurysm or dissection.

This is one reason family history is so important.

What should be in your family history?

If you have aortic disease, your healthcare team may ask whether relatives have had:

• An aortic aneurysm or dissection

• Surgery on the aorta at a young age

• Aneurysms in other arteries

• An unexplained sudden death, especially at a younger age

• A known genetic or connective tissue condition

  
  

Sometimes the connection isn't obvious at first. A relative who died suddenly decades ago may never have received a diagnosis, for example. Sharing as much information as you know can help your healthcare team put the pieces together.

What is genetic testing?

Genetic testing usually involves a blood or saliva sample that is analyzed for changes in genes known to be associated with aortic disease.

Testing isn't necessary for every person with an aortic condition. It may be especially useful when a person develops thoracic aortic disease at a younger age, has other features suggesting a genetic syndrome, or has a family history of aneurysm, dissection, or unexplained sudden death.

A genetic counselor or medical geneticist can help patients understand what testing may be appropriate, what the results mean, and what those results could mean for other family members.

What if a genetic change is found?

Finding a genetic cause can give the healthcare team valuable information.

Depending on the gene involved, it may affect how often the aorta is monitored, which parts of the arterial system need to be watched, and how doctors think about treatment.

It can also help identify relatives who may be at risk.

Many forms of hereditary thoracic aortic disease are inherited in an autosomal dominant pattern. This means that when a parent carries one of these genetic changes, each child may have a 50% chance of inheriting it.

If a specific disease-causing genetic change is found in one family member, other biological relatives can often be tested for that same change. This is sometimes called cascade testing.

What if genetic testing is negative?

A negative genetic test doesn't always mean that genetics aren't involved.

Researchers have identified many genes associated with aortic disease, but we don't yet know every genetic cause. Some families have a clear pattern of aortic disease even when today's genetic testing does not identify a specific change.

That's why doctors may still recommend aortic imaging for close relatives, even when genetic testing doesn't provide a clear answer.

Why does all of this matter?

Aortic disease can sometimes be silent. Someone may have an enlarged aorta for years without feeling anything unusual.

When a genetic or family risk is identified, relatives who feel completely healthy can be screened before an emergency ever occurs. If a problem is found, regular imaging and appropriate medical care can help the healthcare team keep an eye on it and decide whether treatment is needed.

Genetics isn't about predicting the future with certainty. It's another tool that helps patients, families, and their healthcare teams better understand risk and make informed decisions.

If you or a family member has experienced an aortic aneurysm or dissection, especially at a younger age, consider asking your healthcare team whether genetic counseling, genetic testing, or screening for family members may be appropriate.

Knowing your family history could help protect more than just your own aorta.

Thanks for reading, and remember to Think Aorta!

Zach