Updated: Apr 28
Today is Scientific Sunday at Aortic Hope and we are excited to launch our Genetics 101 Series with Ryan Rodarmer.
Over the next couple of weeks, Ryan will discuss a variety of topics related to genetics. Use these discussions as a way to have a conversation with your physician.
Introduction to Aortic Disease and Genetics
Hey all! This is Ryan, Director of Genetic Education for Aortic Hope! I am beginning a blog series to cover several topics related to aortic disease and genetics, including posts about specific genetic syndromes, genetic testing, genetic discrimination, and more. But first, I want to make sure that we're all on the same page before we start talking about the details.
This first post goes over the different ways that genetics can impact our risk for aortic disease. Please reach out to me at email@example.com if you have questions!
Understanding Genetics and Aortic Disease
❓Have you or someone you know been diagnosed with aortic disease? If so, you may be wondering about the role of genetics in this condition.
This is an especially important question if you have little or no lifestyle or dietary risk for aortic disease, if you were young when you were diagnosed (I’m not talking kids, I’m talking before age 60!), or if you have close family members who have similar health concerns. Most importantly, this is a critical question if the aneurysm/dissection involved the root of the aorta (where it connects to the heart) or the ascending aorta (the section of the aorta where it’s still heading north, before the arch and other arteries start branching off).
At this time, aneurysms or dissections/ruptures of this area of the aorta are thought to have a genetic risk factor ALWAYS, even in the presence of other risk factors. In other words... very much influenced by your genetics.
In this blog post and those that follow, we will be diving into the topic of genetics and aortic disease. We will better understand how genetics plays a role in this condition and the genetic differences between the various types of aortic disease.
Remember to #thinkaortathinkfamily!
❓What is Aortic Disease
First, what IS aortic disease? Aortic disease is a condition that affects the aorta, which is the largest blood vessel in the body. It carries blood from the heart to the smaller arteries (although the aorta itself extends way down into the abdomen), which then deliver blood to the rest of the body. Aortic disease can cause the aorta to become weak. The artery may enlarge (form an aneurysm) and/or tear (a dissection or rupture).
An aneurysm usually develops before a dissection or rupture occurs, but sometimes a dissection or rupture happens without an aneurysm. This, however, is much more rare. Usually there’s an aneurysm first. The biggest exception is a condition called vascular Ehlers-Danlos syndrome (VEDS). You may have read about this and concerned yourself with this possibility. I need you to know that this condition is very rare. Like 1 in 100,000 people kind of rare, or maybe even less. I’m getting ahead of myself, because I’ll go into this further in a future blog post about EDS, but most people reading this likely do not need to worry about the possibility of VEDS.
👉Genetics and Aortic Disease
Genetics can play a role in the development and progression of aortic disease in two ways: Mendelian genetic risk factors and multifactorial genetic risk factors (don’t worry! I’ll explain what these mean below).
👉Mendelian Genetic Risk Factors
Mendelian genetic risk factors are caused by a single gene that is passed down from one generation to the next. This type of genetic risk factor is seen in rare cases of aortic disease and is usually inherited in a dominant (50:50) pattern. Dominant inheritance means a child has a 50:50 chance of inheriting the genetic risk from their affected parent. Single genes, dominant inheritance, and a high risk of aortic disease are almost entirely seen in families where the aortic root and ascending aorta are involved. I mention this because families with older onset of aortic disease (after age 60), and especially abdominal aortic disease, usually don’t need to worry quite as much about single-gene causes or high risks to their siblings and children (although there could be some risk... this is discussed in more detail below.)
A feature of dominant disease is that someone can be the first person in their family affected by the condition, as the result of a new genetic difference/typo. However, that person’s children would then have a 50:50 chance of inheriting the condition. Siblings/parents of that person with the new genetic typo generally would not be at increased risk.
👉Multifactorial Genetic Risk Factors
Multifactorial genetic risk factors are caused by the interaction of multiple genes AND environmental (diet and lifestyle) factors. This type of genetic risk factor is more common and is seen in most cases of aortic disease. Families with an older onset of aortic aneurysms located in the descending aorta (and especially the abdominal aorta) are more likely to have familial genetic risks. Lower risks, more heavily influenced by diet and lifestyle, and typically no single genetic cause (no single high-risk gene) that could be found via genetic testing. An obvious exception to this is if there’s abdominal aortic disease present in a family that also has involvement of the aortic root/ascending aorta and/or multiple features that would suggest a known genetic syndrome, such as Marfan syndrome, for example.
👉Hereditary/Single-Gene Thoracic Aortic Disease: Syndromic and Non-Syndromic Inheritance
There are two main types of hereditary thoracic aortic disease: syndromic and non-syndromic.
👉Syndromic Thoracic Aortic Disease
Syndromic thoracic aortic disease is when aortic disease is part of a larger genetic syndrome, such as Marfan syndrome. In these cases, aortic disease is just one symptom of a larger genetic disorder, affecting other areas of the body as well. The next few blog posts will talk about specific genetic syndromes that cause thoracic aortic disease.
👉Non-Syndromic Thoracic Aortic Disease
Non-syndromic thoracic aortic disease is when aortic disease risk is the only symptom being inherited and is not part of a larger genetic syndrome.
In conclusion, genetics plays a role in aortic disease through both single-gene (or hereditary) and multifactorial (or familial) genetic risk factors. Additionally, there are two main types of hereditary thoracic aortic disease: syndromic and non-syndromic. In this upcoming blog series, we'll talk about specific genetic conditions, testing, and possible unfair treatment related to genetics. Our goal is to help you understand this topic better and feel more confident as you discuss your management and testing options with your doctors.
Understanding the role of genetics in aortic disease is crucial for both patients and their families. As we've discussed, genetics can play a role through single-gene (or hereditary) risk factors and multifactorial (or familial) risk factors. We also delved into the two main types of hereditary thoracic aortic disease: syndromic and non-syndromic. This blog series aims to empower you with knowledge, helping you feel more confident when discussing your management and testing options with your healthcare professionals. In our next blog post, we'll dive deeper into Marfan syndrome, a specific genetic condition related to aortic disease. Stay tuned, and remember to #thinkaortathinkfamily!
The views, information, and opinions presented here are those of the individual(s) involved and do not represent the opinions of The Marfan Foundation. The Marfan Foundation is not responsible for and does not verify for accuracy any of the information contained here, nor does the information constitute medical or other professional advice or services. This website is not produced by or affiliated with The Marfan Foundation or The VEDS Movement.