Congenital Heart Disease Care Model: Genetics

This is the second entry in our blogpost series that describe the different aspects of the Congenital Heart Disease Center's multi-disciplinary model of care. In this post, the role of Medical Genetics in care of CHD patients is examined and explained by Mayo Clinic Rochester medical geneticist and physician David Deyle, M.D. and genetic counselor Katherine Agre.

“The overall goal of what I do in the clinic is see patients and assess them for possible genetic underlying connective tissue disorders” said David Deyle, M.D. who along with genetic counselor Katherine Agre, work together with congenital heart disease patients to determine and explain genetic factors and roles within their treatment.

The two primary patient groups that Dr. Deyle and Ms. Agre work with are patients with Marfan syndrome and Loeys-Dietz syndrome. Dr. Deyle stated that some disorders have been recognized for a long time such as Marfan syndrome, but also notes that Loeys-Dietz syndrome was discovered much more recently. Additional genetic causes of cardiac disease are uncovered frequently.  This continued expansion of knowledge is critical to our long-term understanding of the cause and treatments for these diseases.

Dr. Deyle and his team generally first meet a patient when they are diagnosed with aortic dilation. With the genetic testing, they are may be able to help identify the underlying diagnosis for the patient and thus recognize what other medical issues may come in the future.  This allows for appropriate screening and early recognition and treatment of new symptoms.  This may require coordination with a diverse range of other departments or specialists.

Currently, challenges largely stem from the unknown genes. At this time, the genes that are responsible for Marfan syndrome or Loeys-Dietz syndrome are known and the recognition of these genes is continually improving. However, difficulty comes when patients look outwardly normal, and it especially comes with babies born with congenital heart defects. Deyle explains,

“When we start talking about congenital heart disease in children that are born with a structural heart defect, the challenge is finding genes that may lead to it. What causes  abnormal development and is there a genetic component?” He continued, “There are 20 to 25 thousand genes that make up the genome. We only know what about five to seven thousand of those genes do. That’s what I think is the biggest challenge, is the knowledge of what the entire genome does.”

As these genetic factors are studied and understood genetic counselor Katherine Agre is brought in to assist in educating the patient and family on topics such as personal and family history or risk for different conditions due to the genetic factors. Agre detailed:

“Our goal is to bridge the gap between the really complex genetic information that is out there, really the mechanism between the disease, and the patients and their families, to make this information helpful to them and help them utilize it to help their families understand and make good medical choices.”

The emotional needs of the patient is also incredibly important in these circumstances, especially when it comes to discussing genetic factors with parents of newborns with congenital heart defects. Agre says that the most difficult part of those conversations is helping the parents with the guilt they feel of potentially passing CHD to their child. Agre elaborates,

“Acknowledging that is a big part of it, and that it is a really normal response. Parents want the best for their children, they want their children to be happy and healthy and live long healthy lives. If there is something genetic, you have no control over passing this down. Or if it’s something new in a child, it isn’t something you did or didn’t do, or could’ve controlled in any way.”

There is still much to learn and understand about the genetic code, but the inclusion of studying genetics within the congenital heart disease care model maintains its importance, “Knowing is half the battle” Dr. Deyle intimated. “You can identify those patients really young who need to be monitored as they go through life. It’s important to know which patients to screen, to avoid certain lifestyle choices.  There is a lot of important information to be learned from genetics that can really impact how you are going to treat an individual patient.

HELPFUL LINKS

• Learn more about the Center for Congenital Heart Disease
• Connect with others talking about heart conditions on Mayo Clinic Connect.
• Explore Mayo Clinic's Rochester campus and the Mayo Clinic Health System.
• Request an appointment.