The facts don't lie. More than 1.6 million adults in the United States are genetically inclined toward heart failure. Wouldn't it be helpful to know if you have a familial risk of developing heart disease?
"About one in 200 people in the United States has an inherited risk of cardiovascular disease," says Dr. Burns C. Blaxall, Director of Precision Medicine at The Christ Hospital. "With recent advances in hereditary cardiovascular risk evaluation, patients and their families can be tested for a genetic predisposition to developing heart disease."
Thanks to one Ohio family and The Christ Hospital's cardiovascular genetic counseling program, the link between one genetic variant and one heart condition—called dilated cardiomyopathy (DCM)—has recently been identified and confirmed.
Paige Gabbard of Preble County, was diagnosed with DCM in her early forties. The condition results in the weakening and enlargement of the heart muscle and limits the heart's ability to pump blood. When two of her siblings subsequently developed heart failure, she thought there might be a familial link. Last year, after Gabbard's 20-year-old nephew was diagnosed with sudden heart failure, she sought genetic counseling in the hopes of identifying the disease potential in other family members.
"I had a gut feeling there was a connection between all of us, as family members, and our heart failure," says Gabbard, now in her late 50s. "I felt genetic testing would be an invaluable way to identify the risk for our remaining family members. I don't want them to wait until it's a matter of life and death."
Gabbard met with Bryana Rivers, a licensed genetic counselor at The Christ Hospital, to determine if there was a hereditary cause to the condition. When Gabbard's test results came back, there were two genetic variants reported. Rivers determined that one of them—the BAG3 variant, previously suggested to impact the development of DCM—seemed suspicious as the possible cause of DCM in this family.
"Although a genetic change may be present, it does not necessarily have an impact on one's health," says Rivers. "It could just be a benign variation of normal." However, she explained to Gabbard that the results warranted testing other family members for this variant. "If those who have DCM in the family have this same genetic change, and those who do not have DCM do not carry it, that makes it more likely to be the cause of DCM in the family."
Rivers then tested Gabbard's nephew and brother, who also have DCM. Gabbard and her siblings share a 50 percent likelihood of carrying the same genetic variant. The presence of the same variant in her nephew, who could only have a 25 percent chance, would more strongly indicate a connection between a gene variation and a shared heart condition.
When the results came back, it was confirmed: the tests indicated the same BAG3 variant in those family members with DCM. "We were then able to offer testing for this newly reclassified BAG3 variant to the family, at no additional cost," says Rivers. "I have subsequently tested multiple family members, both affected and unaffected."
According to Blaxall, the genetic testing performed on this family resulted in amending the designation of the BAG3 variant from "uncertain significance" to "likely disease-causing" for DCM. "Going forward, when genetic testing is done on other people, this variant in the BAG3 gene can indicate—to anyone around the world—that the mutation may result in cardiovascular disease."
Gabbard, her brother, and one of her sisters, who all suffer from heart disease, tested positive for the BAG3 variant; her other sister did not and has exhibited no symptoms of heart disease to date. Testing was also recommended for Gabbard's four children, particularly the youngest, who has children of her own. Her 20-year-old nephew who prompted Gabbard to seek genetic counseling is now doing well after receiving a surgically implanted VAD, or ventricular assist device, to correct his failing heart.
"After what happened to my nephew, we know this disease doesn't wait until middle age to strike," says Gabbard. "It can hit at any time."
Although considerable heartache was involved, Gabbard is gratified that her family could help others by confirming the BAG3 variant. "It's certainly quite the adventure to be notable for a scientific discovery," she says and adds with a laugh, "I guess that kind of makes me a BAG3-Lady!"
Blaxall says this branch of medicine—called "precision medicine" or "personalized medicine"—has three approaches to health care: familial hereditary risk, clinical diagnostic decision support, and pharmacogenomics, which uses genetic testing to assist with precision medicine prescribing. "Precision medicine is the future of health care," says Blaxall, who explains that this science is designed to tailor the diagnosis, prevention, and treatment of individual patients based on each patient's unique genetic makeup. "It represents the transition from reactive to proactive health care."
The Christ Hospital recommends genetic testing for individuals diagnosed with cardiomyopathy, arrhythmia, certain types of vascular disease, familial hypercholesterolemia, and congenital heart defects. "At The Christ Hospital, we want to help you and your family understand any inherited risks," says Blaxall. "Genetics is not destiny. Our goal is to partner with you to be significantly more proactive in your health care."
Learn more about cardiovascular genetic counseling at The Christ Hospital or call 513-585-3275.