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Hypertrophic cardiomyopathy (HCM) is the most common form of genetic heart disease. A person can inherit the gene mutation that causes it or the gene mutation can happen for unknown reasons in someone without a family history.
Genetic testing is a tool that may help you and your family understand more about HCM and its risks. This testing looks for changes in your genes that could be causing HCM.
Purpose of genetic testing in hypertrophic cardiomyopathy
Doctors recommend that people with an HCM diagnosis consider genetic testing. It is important to work with your doctor, a genetic counselor, or both to understand the testing process.
Reasons your doctor or genetic counselor may suggest genetic testing can include:
- Confirming the diagnosis: Genetic testing may help your doctor diagnose HCM if other test results are unclear.
- Ruling out other diseases: Genetic testing can tell HCM from other conditions with similar symptoms.
- Predicting outcomes: Typically, genetic testing cannot predict disease progression. However, some genes may have links to a higher risk of mortality or a lower risk of heart problems.
- Planning treatment: Genetic testing can help your doctor determine treatment options.
- Family screening: Genetic testing may identify family members who are at risk. These people can follow up with a heart doctor, a process commonly known as cascade screening.
The genetic testing process
Your doctor or genetic counselor will lead you through the genetic testing process. It includes the following steps:
- Pre-test genetic counseling: You will learn about the types of tests, what the results could mean, and the benefits, risks, and uncertainties of the testing.
- Sample collection: You will give a blood or saliva sample for the genetic testing.
- Lab analysis: A lab will compare your genes to standard genes and a database of genes from people with known HCM.
- Result interpretation: An expert will classify any changes in your genes based on how strongly they link to HCM.
- Post-test counseling: You will learn the test results and how they affect you and your family members.
Interpreting genetic test results
Genetic test results are not always easy to understand. Your doctor or genetic counselor will go over the results with you. They can explain exactly what the results do and do not mean.
Results can include:
- Positive: The test found a pathogenic (disease-causing) or likely pathogenic gene. However, having a positive result does not always mean a person will develop HCM.
- Negative: The test did not find genetic changes, or it found genes with harmless changes.
- Inconclusive: The test found a rare genetic change, but it is unclear whether it is related to HCM. This is called a variant of uncertain significance (VUS).
Who should consider genetic testing?
Anyone with HCM, potential HCM, or a relative with HCM can consider genetic testing. However, there are many things to consider, including how it may affect you emotionally or physically. Your doctor or genetic counselor can help you decide if it is right for you.
Talk with your doctor or counselor if you are:
- Someone with confirmed HCM: Consider testing to find the specific genetic cause of your HCM.
- Someone with an uncertain diagnosis: Consider testing to confirm a diagnosis with genetic evidence.
- First-degree relative of someone with HCM: Consider testing if you are a parent, sibling, or child of someone with HCM who has had a positive genetic test.
- Athlete with heart changes: Consider testing to find out if changes in your heart are a standard result of strenuous activity or if it is HCM.
Genetic testing is a useful tool for diagnosing HCM and for screening people who may be at risk. However, as with any medical test, you can consider its risks and benefits. While genetic testing plays a vital role in HCM care, it may not be right for everyone.
Your doctor or genetic counselor is the best source for learning about the benefits and limitations of genetic testing. Together, you can decide if it is the next step in your care journey.