February is American Heart Month, so it's a great time to take heredity to heart and learn why genetics is important in heart disease. Cardiovascular genetic counselors specialize in providing risk assessment and, when heredity is indicated, genetic testing for heart disease. Since cardiovascular disease, including heart disease and stroke, is the leading killer of American men and women, knowing whether you may have an increased genetic risk is very important.
Most types of heart disease, including abnormal heart rhythms (arrhythmias), aneurysms and heart attacks, can have a hereditary component. If you find a genetic risk for heart disease, you can help prevent or treat it before symptoms begin.
Heart Disease and Genetic Testing
For those whose family has heart disease with known genetics links, genetic testing may be able to identify the exact DNA change predisposing the family to the disease. This allows at-risk relatives (including children) to undergo predictive genetic testing.
Most DNA changes associated with hereditary types of heart disease are passed through families in an autosomal dominant pattern. This means the condition can affect males and females. It also means all first-degree relatives (parents, siblings and children) of affected individuals have a 50 percent risk of inheriting the predisposition. Relatives with the predisposition will likely require cardiac screening over the years to help diagnose heart disease as early as possible. Relatives without a predisposition likely have no increased risk for the heart disease running in the family.
For those with inherited heart disease, treatment options may include medications and in some cases, implantation of a device to make sure the heart beats in the proper rhythm and/or that the heart pumps the right amount of blood to the rest of the body. In some cases, surgery or other treatments also are available.
“Complex” Heart Disease
There are also “complex” forms of heart disease. This means the condition is due to a combination of risk factors. One such complex disease is coronary artery disease, the most common type of heart disease. It happens when blockages form in the coronary arteries, which supply oxygen to the heart. There are multiple risk factors for coronary artery disease, including high blood pressure, high cholesterol, smoking, as well as genetics and family history. Many studies have shown that about half of coronary artery disease is due to hereditary factors. But, all of these risk factors combined lead to a person's risk profile for coronary artery disease.
For most patients and families with coronary artery disease, there is currently no test that is able to look for all possible genetic risk factors and provide an accurate risk prediction. One exception is for the condition familial hypercholesterolemia (FH), which is a common genetic cause of early-onset heart disease. Genetic testing is available for FH. For other types of familial coronary artery disease, the patient's personal medical and family histories are very important in helping to determine the right path for proactive prevention.
Red Flags for Hereditary Heart Disease
Watch for these signs in your personal and family health history, starting with your grandparents back to your generation:
- Heart disease at a young age (younger than 55 in men, younger than 65 in women)
- Sudden death in a family member who seemed healthy. This also includes sudden accidental deaths including drowning and single motor vehicle accidents.
- Exercise intolerance
- Heart failure or heart transplant at younger ages
- Multiple relatives with pacemakers or implantable defibrillators
- Sudden infant death syndrome (some cases have been shown to be linked to mutations in genes that are also associated with hereditary arrhythmias)
If you see these red flags in your family tree, you should inform your doctor and ask whether cardiovascular genetic counseling and testing may be right for you. The earlier you are able to identify hereditary heart disease, the better, for you and your children. These signs can be the key to identifying, treating and even preventing genetic heart disease.
To learn about your inherited risk for heart disease and genetic testing options, use NSGC's Find a Genetic Counselor tool.
Amy Sturm, MS, CGC, LGC is a cardiovascular genetics expert for the National Society of Genetic Counselors and an associate professor and genetic counselor in the Division of Human Genetics at the Ohio State University Wexner Medical Center in Columbus, Ohio.