Genetic program at MUSC tests for hereditary heart disease, cancers

The MUSC Cardiovascular Genetics program helps patients understand their own DNA while revealing more about genetic diseases throughout the region

by Celia Spell

Actor and screenwriter Chadwick Boseman died in 2020 of colorectal cancer at age 43. 

Originally hailing from Anderson, S.C., Boseman is best known for his role in the breakout superhero movie Black Panther. And while there were multiple risk factors contributing to his ultimate diagnosis, family history certainly played a role: His brother was diagnosed with colorectal cancer soon after he was. 

The genes that tie families to a shared ancestry can also reveal a predisposition for certain genetic diseases and conditions like Boseman’s. And with the rise in accessibility and rapid decrease in cost, genetic testing has become a popular method for identifying which genes we carry and options for potentially avoiding or lessening their impact. 

Whether someone is looking for general DNA sequencing or specialty programs, knowing your individual risks can be helpful. 

Daniel Judge, M.D., the Edwin & Teresa Rogers endowed professor at MUSC, started the MUSC Health Cardiovascular Genetics program to specifically address the state’s leading cause of death: heart disease. 

Kim Foil, CGC, a genetic counselor with the program, says it’s the only cardiac genetic center in the state and one of only a few in the Southeast. 

“It’s rare for a genetic counselor or even a genetic program to focus their practice exclusively on cardiology,” she said. “And it’s the support and interest of a physician like Dr. Judge who can really utilize genetic counselors and their capacity that has allowed our program to grow. It’s certainly not something every academic center has.” 

Testing

Foil says she sees people with a variety of cardiac conditions, and her goal is to find out if there is an underlying genetic reason for their recent diagnosis or current symptoms – information which could give them answers but could also have implications for their care. 

Whether it be a cardiomyopathy, arrhythmia, connective tissue disorder or amyloidosis, patients at MUSC can meet with a cardiac genetic counselor to discuss their medical and family history, as well as learn what their results mean for them and their relatives. 

Naomi Barker, CGC, a cardiac genetic counselor at MUSC who works alongside Foil, enjoys teaching patients about genetic testing. 

“It’s truly a dialogue between the genetic counselor and the patient,” she said. “Genetic testing is not required – it’s an option for them to pursue if they want that information. And that’s not always the case with medical tests.” 

Knowledge of genetic information is not something that can be undone or unlearned, and it impacts family members as well, so Barker tries to offer consent in an informative way. 

After discussing what genetic testing is, understanding the risks for family members and identifying the chance for something to be inherited or passed on, patients can make an informed decision about next steps, if any. Barker and Foil also discuss the complexity of sharing that information with relatives whose lives may be affected by their shared DNA. 

Judge is clear to point out that just because someone tests positive for an abnormal gene, they are not doomed to receive a negative diagnosis. The presence of an abnormal gene suggests a predisposition or risk for a condition in their lifetime, not a confirmation of one. The opportunity to make a difference is one of the things that excites him so much about genetics. People can make lifestyle changes to stave off the disease or schedule scans and tests more often to catch the problem early. 

“Sometimes people carry a genetic abnormality towards cardiomyopathy or aortic disease,” he said. “And then they never develop the problem, but their family member does. So, identifying risks and starting medication at an early stage to prevent more problems later on are our main motivations.” 

With hypertrophic cardiomyopathy (HCM), for instance, patients may not experience any symptoms before a sudden cardiac event, and HCM is the most common cause for sudden cardiac death in athletes according to the American Medical Society. But since it has a genetic cause, preventative measures can be taken if a relevant gene variant is identified or if a patient knows it’s part of their family history. An implantable defibrillator may be placed under the skin to treat life-threatening arrhythmias. Patients may also need to avoid endurance activities such as marathon training, but these lifestyle changes and surgical options are only available if the risk is caught early. 

Foil says the team’s focus on family history is what makes the program unique. Through an hour-long session, Foil and Barker discuss the diagnoses, ages and causes of death for at least three generations of family members, if possible, to craft the clearest picture of an individual’s genetic information. 

“After these sessions, a patient might start to realize that over half their family has been affected by the same condition,” Judge said. “But no one had taken the time to do an in-depth family history to find out until now.” 

And with clinical testing as inexpensive as $250, Judge says it’s more accessible than it’s ever been for people with a family history of HCM or any other heart disease. 

Research

As part of a population genomics screening program designed to identify risks of certain conditions in South Carolina and expand the data in anonymous genetic registries about the Southeast, Judge is also leading a study called In Our DNA SC. Through a strategic collaboration with genomics company Helix, Judge is hoping the research will help physicians and researchers understand what’s common in the region and what’s tied to DNA. 

With a statewide initiative to enroll 100,000 patients in the program over the next 4 years, In Our DNA SC offers genetic screening for some conditions at no cost to participants. In the first year alone, Judge and his team have enrolled more than 20,000 adults across the state. 

Judge points to Iceland as an example of a region with a robust and well-characterized cohort of people who’ve been there their whole lives, and he hopes improving South Carolina’s database will provide insights regionally and help improve the overall standard of care as well as grow treatment options. 

Genetic tests remain accurate and effective by testing for specific gene mutations. While diseases can have both simple and complex genetic causes, In Our DNA SC focuses initially on conditions related to abnormalities in 1 of 11 genes. These are categorized as Tier 1 by the Centers for Disease Control and Prevention because of their potential for positive impacts on public health. By testing for 11 genes relating to breast cancer, ovarian cancer, colorectal and endometrial cancer and increased risk for heart disease or stroke, the MUSC team prioritizes diseases and conditions whose risks can be significantly decreased or even prevented if detected early. 

Preliminary results show that around 1 out of every 75 participants will have a positive result which will give them information they can act on and will include free genetic counseling. With the hope of expanding clinical genetic testing, including pharmacogenetics, the data collected will soon be available to support other research efforts at MUSC. 

Both clinical and research efforts to improve recognition of inherited conditions rely on the work of genetic counselors like Barker and Foil. And as they have helped to build a newer field with a lot of growth over the last decade, they’ve enjoyed following its evolution. 

“We’re giving patients a better explanation for why something happened,” she said. “I think it can help people relieve their guilt, burden or shame that can come from being sick. We’re helping people rewrite their story.”