Genetic testing can be a powerful tool in the management of cardiomyopathy. Familial cardiomyopathy is a disease of the heart muscle that is passed down through a family’s genes. It is a very serious disease that can lead to heart failure and is a frequent cause of sudden cardiac arrest in children.
These five types of cardiomyopathy can be related to a person’s genetic makeup:
- Dilated cardiomyopathy (DCM)
- Hypertrophic cardiomyopathy (HCM)
- Left ventricular non-compaction (LVNC)
- Restrictive cardiomyopathy (RCM)
- Arrhythmogenic right ventricular cardiomyopathy (ARVC)
Familial cardiomyopathy is caused by a change, or mutation, in a gene. The good news about this is that genetic testing often can identify the gene mutation. Then, other family members can be tested for that specific mutation. We can then determine if those individuals could be at risk for also developing cardiomyopathy.
The benefits of knowing this genetic information are many. You may learn answers to questions such as, Could my child one day develop this disease? What symptoms should I be on the lookout for? Should I or my family members be seen regularly by a cardiologist? Is it OK for my child to play sports?
At our Cardiomyopathy Program, we see both adults and children with cardiomyopathy. Genetic testing is one component of the comprehensive care we provide these families. When someone is considering genetic testing for cardiomyopathy, these are the questions I hear most often:
What is involved in genetic testing?
Testing is done with a simple blood draw. (For someone with an extreme phobia of needles, a saliva test could be an option.)
For the first family member getting testing done, the results will be ready in about three to four months. Once ready, one of our genetic counselors will call you to explain the results. You can also make an appointment to come in and discuss your results.
Is the cost covered by insurance?
In many cases, health insurance plans will cover all or part of the costs of genetic testing when a doctor recommends it. However, health insurance providers have different policies about which tests are covered. Our genetic counselors help navigate the insurance system so you know prior to testing what to expect.
If you’re uninsured, our counselors can work with you to find a program that could help cover the cost, or to work out a payment plan.
Will a positive result affect my or my child’s ability to get health insurance?
A federal law named the Genetic Information Nondiscrimination Act (GINA) was passed in 2008 making it illegal for a health insurance company to change your premiums or deny you coverage based on genetic test results. This means that even if you need to change health insurance companies, the new company cannot discriminate against you or your family based on a genetic test result.
What do the results mean?
We first start with genetic testing in a family with an individual who has been diagnosed with a form of familial cardiomyopathy. Let’s say I see an adult patient named Sarah who has hypertrophic cardiomyopathy. We do genetic testing on her and find out she has a gene mutation that caused her heart disease. We then test her son, Michael, to see if he has the same gene mutation.
If Michael’s test results are negative, this means he did not inherit the gene mutation that caused the cardiomyopathy in his mother. In this case, routine cardiac screening would not be recommended for Michael. Essentially, he is “in the clear” for this form of cardiomyopathy and would not have to return to a cardiologist for this particular condition. Families who receive a negative result often say it gives them a great sense of relief and peace of mind.
If Michael’s test results are positive, this means he did inherit the gene mutation that caused the cardiomyopathy in his mother. In this case, Michael:
- Might already have the disease but has no symptoms yet,
- Might already have the disease with the symptoms wrongly attributed to another medical condition, or
- Might not yet have the disease but is at risk to develop it later in life.
With these results in hand, Sarah and Michael can now better prepare themselves for the road ahead of them. They will know that Michael should be followed by a cardiologist for the rest of his life. They’ll learn what symptoms to watch for. They’ll find out if Michael needs to make certain lifestyle changes, such as limiting sports. Because the end result of this disease is sometimes a sudden and unexpected death, having the genetic test results can be very empowering.
If Michael had children, I would recommend that they go through genetic testing as well.
While this may be a simplified example, I hope it helps families get a better sense of how powerful genetic testing for cardiomyopathy can be. If you are considering genetic testing for your family, please keep in mind that it does have limitations. We don’t yet know all of the gene mutations that cause cardiomyopathy. Sometimes the test comes back with what is called an uninformative or inconclusive result. Whatever your results, we will take the time to fully explain them so you are better educated about your and your family’s heart health.
Editor’s note: We hosted a live event in Sept. 2015, in which John Lynn Jefferies, MD, and Ivan Wilmot, MD, answered questions from families about genetic testing for cardiomyopathy. You can watch the broadcast here.