Hypertrophic Cardiomyopathy Association

Learn About Genetic Testing in HCM.

Cardiac Genetic Testing

Genetic testing is quick and easy – A small sample of blood or saliva (spit) is sent to a lab which tests for genetic causes of HCM.

Why get tested? A genetic test looks for changes in your DNA that may explain why you have a thick heart.

Scientists keep discovering new genetic causes of HCM.

When you have HCM, it is best to have your genetic testing and other HCM care at a Center of Excellence (COE).

A COE has a team of doctors who have seen HCM in all its forms. These centers are more likely to understand your HCM than a general cardiology office.

If you can’t afford to travel to a COE, we offer the Lori Fund to help cover travel costs so you can get the care you need.

A genetic test result is “positive” if a mutation is found.

A positive result doesn’t usually change how doctors treat or monitor your HCM.

Sometimes, having a genetic mutation can make you eligible for a clinical trial . These are safe and controlled ways to test new treatments for HCM, like gene therapy.

  • Each copy of each gene you have (you have 2 of each) has a 1 in 2 (50%) chance of being passed to each child.
  • If you have one of the sarcomere mutations known to promote HCM, each of your children has a 50% chance of inheriting that gene mutation. Their chance of inheriting HCM itself is less than 50% since not everyone with one of these mutations develops disease.
  • If you have HCM but no known mutation, your kids still have a chance of inheriting HCM. We don’t know what that chance is, though, because we don’t understand all the causes of HCM. There is some evidence suggesting that people with non-sarcomere HCM don’t pass on the phenotype as easily as those with sarcomere HCM.
  • A “genetic test” doesn’t test whether your HCM is caused (or partly caused) by genes. It tests whether you have one of the known mutations. In other words, a negative genetic test doesn’t mean you can’t pass your HCM on to your kids. The reason for testing isn’t to exclude YOU, it’s to possibly exclude them from further concern – if you have a known mutation and they don’t, then their chances of developing HCM are exceedingly small, effectively zero.
  • Family members who have the mutation (including your children) can benefit from getting specialty HCM monitoring and/or care as early as possible.

If you have a negative test result, you can get tested again in the future to check for any new causes. Another possible test result is a VUS (or variant of uncertain significance). This means there’s a change in your DNA, but there’s not enough information about whether it causes HCM. Just like a negative result, you and your close family still need to be followed for HCM.