Sabrina Cuddy • March 21, 2024
April’s Topic is Genetic Testing

Who should have genetic testing, why, and when?

Suppose you have been clinically (through an EKG, echocardiogram, and a visit with a cardiologist) diagnosed with HCM. In that case, most experts recommend that you have genetic testing to determine the underlying reason your heart is too thick.

Why does it matter?   

Some hearts look like HCM but have a specific genetic mutation for one of the HCM spectrum disorders – Amyloidosis, Fabrys, Danon, Sarcoidosis, etc. These disorders are often managed differently from HCM alone, so you need to know if you have one.

HCM is mainly caused by gene mutations (sometimes called variants or markers). Not all HCM is linked to a specific variant, and we believe more mutations will be identified in the future. 

In recent studies at large HCM Centers, about 40% of those tested had a gene mutation known to cause HCM. As of 2023, 60% will not have a mutation currently identified as causing HCM. It is still believed that HCM is a genetic disorder that families can pass down – even if the mutation is currently unknown. 

Your genetic test can show one of three results:

  • Positive / Mutation identified (you have a known variant). 
  • Negative / No mutation identified (you do not have a known variant).
  • VUS (a variant of uncertain significance whose meaning is still evolving). It’s a bit confusing, but as researchers learn more, a VUS can be reclassified as a positive or negative.

If your genetic test is positive, this information can be used to screen family members to see if they have the same variant.  Your children, parents, and siblings can be tested for your variant, and if they don’t have it, they can skip clinical tests (echocardiogram, etc.) unless they develop heart symptoms. 

A negative genetic test DOES NOT take away your HCM diagnosis ,  and it DOES NOT mean that your family can safely avoid clinical screening for HCM  (echocardiogram, EKG, and an exam by a cardiologist). Researchers are still discovering variants that may cause HCM and are starting to look into combinations of two or more genetic variants ( polygenetic ) that could cause HCM. If you do not have a known variant, your close relatives must be screened regularly using clinical tests to see if they develop HCM. 

Once you’ve gone through our free  Intake  process, we will invite you to join our new  Nest  education program.  For a great explanation of genetic testing in HCM, sign up for the Nest portal when you’re invited.

Knowing your mutation may allow gene therapy to treat your HCM in the future. Clinical gene therapy trials for those with a mutation on MYBPC3 have started! We expect other common HCM variants (such as MYH7, etc.) to be included in future clinical trials.

A last thought: many people who test positive for one of the known variants say, “I have the gene for HCM,” but this is misleading. They have a mutation on one of many genes that may contribute to HCM.For more information about genetics and genetic testing, please visit the HCMA website at  https://4hcm.org/genetic-testing-an-overview/  and  https://4hcm.org/genetic-testing-other-considerations/.

HCMA Blog

By Lisa Salberg October 10, 2025
The Price of Love: A Tribute to Esther
By Sabrina Cuddy August 1, 2025
On a background of pink
By Julie Russo July 31, 2025
Sixty years ago, Medicaid and Medicare were established when President Lyndon B. Johnson signed the Social Security Amendments into law. The programs were a larger part of Johnson's "War on Poverty" agenda to combat inequality. Sixty years later, Medicaid and Medicare are under attack in ways that we could never have imagined. With the passage of the One Big Beautiful Bill Act (OBBBA), $1 trillion was cut from Medicaid and Medicare―the largest health care cut in U.S. history. As a result of the budget package, more than 15 million people will lose health insurance, hundreds of rural hospitals will close, and approximately 51,000 people will die preventable deaths each year. Congress voted for this harm, and Congress can fix it. We need them to invest in Medicaid and Medicare in order to undo this damage. Click here to send a message to Congress telling them to invest in these critical programs, not cut them. OBBBA is the exact opposite of the "War on Poverty." The bill was passed with brutal cuts to health care to fund more tax handouts for the very wealthy. It took from the poor to give to the rich. The unpopularity of these cuts cannot be overstated. Eighty-three percent of the American public, including three in four Republicans, has a favorable view of Medicaid. Congress must hear from us loud and clear: reverse course, undo the harm to Medicaid and Medicare, and protect health care for more than 71 million people. Join us in sending the message to Congress to invest in these critical programs, don't cut them. 1 The Truth About the One Big Beautiful Bill Act’s Cuts to Medicaid and Medicare 2 Research Memo: Projected Mortality Impacts of the Budget Reconciliation Bill 3 Medicaid keeps getting more popular as Republicans aim to cut it by $800 billion
More Posts