Hypertrophic cardiomyopathy (HCM) may sound rare, but it isn’t. This condition affects an estimated one in 250 to 500 people in the United States, according to the Cleveland Clinic. Yet many people may not realize they have it until symptoms appear — or worse, until a cardiac event brings it to light.
HCM is a type of heart disease that causes the heart muscle to thicken. That thickening makes it harder for the heart to pump blood effectively, and in some cases, it can block blood flow entirely.
If you’ve recently been diagnosed with HCM, you probably have a lot of questions. One of the biggest is: Is hypertrophic cardiomyopathy genetic?
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The answer is yes — and for Black patients in particular, understanding the genetic link is critical.
Does Hypertrophic Cardiomyopathy Run in Families?
HCM is primarily genetic. Cardiologist Maran Thamilarasan, MD, of the Cleveland Clinic, explains that known genetic mutations are identified in about 60 percent of cases.
That means if one parent carries one of these mutations, each child has about a 50 percent chance of inheriting it. Both types of HCM — obstructive (which blocks blood flow) and non-obstructive (which does not) — can be inherited.
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Still, there are unanswered questions. Scientists continue to discover new genes that may cause HCM. And even among those who inherit a gene mutation, not everyone develops the disease.
One study found that about 16 percent of people who were gene-positive developed measurable traits of HCM over seven years. In other words, carrying the gene doesn’t always mean the condition will show up, but the risk is real enough that families should take it seriously.
RELATED: Understanding HCM: What You Need to Know
Why Black Patients Need Special Attention
While HCM can affect anyone, race plays a role in how it’s diagnosed, treated, and even understood.
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Delayed diagnosis: Research shows Black patients with HCM are often diagnosed later than white patients. That delay increases the risk of complications like arrhythmias or heart failure.
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Misdiagnosis: Symptoms of HCM — such as shortness of breath, chest pain, or palpitations — are sometimes mistaken for hypertension, asthma, or anxiety in Black patients.
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Limited access to genetic testing: Black patients are less likely to be offered genetic counseling, even though their risk may be just as high.
This matters because untreated HCM can lead to life-threatening complications, including atrial fibrillation, congestive heart failure, and sudden cardiac arrest.
Early recognition — paired with genetic screening — can literally save lives.
Should Your Family Get Genetic Testing?
If you’ve been diagnosed with HCM, your immediate family (parents, siblings, children) should strongly consider genetic testing.
“Often, we don’t make a diagnosis early enough. Some people with the condition are at higher risk for cardiac events, and we need to know about it,” Dr. Thamilarasan says.
Genetic testing usually involves a simple blood or saliva test to identify changes in your genes. But it doesn’t stop there. Doctors may also recommend follow-up tests such as:
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Exercise stress echocardiogram
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Cardiac event monitor
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Cardiac MRI
Another key reason to test: symptoms of HCM can overlap with other conditions.
Conditions that Mimic HCM (“Phenocopies”)
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Hypertension (high blood pressure)
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Cardiac amyloidosis (protein buildup in the heart)
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Fabry disease (a rare genetic disorder)
Each of these can cause thickened heart muscle, but treatments differ. Genetic testing helps clarify whether it’s really HCM or another condition that requires a different care plan.
Questions to Ask Your Doctor About HCM and Genetics
If you or someone in your family has hypertrophic cardiomyopathy, bring this checklist to your next appointment:
Genetic Risk
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Could my HCM be genetic?
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Should my parents, siblings, or children be tested?
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How do we arrange genetic counseling?
Testing & Diagnosis
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Which tests should I (or my family) have besides genetic testing?
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Could my symptoms be caused by something other than HCM (like hypertension or amyloidosis)?
Treatment & Lifestyle
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What lifestyle changes are safe and effective for me?
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Are there exercises I should avoid?
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Should I limit caffeine or alcohol?
Medication & Procedures
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Do I need medication now? If so, which kind?
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Would I ever need surgery or an ICD?
Long-Term Monitoring
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How often should I have follow-up appointments and imaging?
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What warning signs should I look out for?
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How do I reduce my risk of sudden cardiac arrest?
Tip for Black patients: Ask specifically about genetic counseling and access to specialized HCM clinics — these services are sometimes offered less often, but they’re just as important.
RELATED: What You Need to Know About the Latest HCM Guidelines
What to Do If You’re High Risk
HCM is lifelong, but that doesn’t mean you’re powerless. Depending on your risk and symptoms, your healthcare provider may recommend:
Lifestyle Changes
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Eat a heart-healthy diet (fruits, vegetables, whole grains, lean proteins, healthy fats).
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Limit alcohol and caffeine, which may trigger arrhythmias in some patients.
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Aim for quality sleep to support cardiovascular health.
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Stay physically active — but under guidance. Not all exercises are safe for people with HCM.
Medications
Your doctor may prescribe:
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Beta-blockers
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Calcium channel blockers
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Diuretics
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Myosin inhibitors (a newer class of medications for HCM)
Procedures or Surgery
For some patients, surgical interventions are necessary, such as:
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Septal myectomy (surgical removal of part of the thickened heart muscle)
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Alcohol septal ablation (using alcohol to shrink part of the thickened septum)
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Implantable cardioverter defibrillator (ICD) to prevent sudden cardiac death
What Makes HCM So Complex
The genes that may cause HCM are those responsible for building and maintaining the heart muscle’s structure. While the disease can affect any part of the heart, it often thickens the septum (the wall dividing the left and right sides).
This thickening can:
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Block blood flow from the left ventricle to the aorta.
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Stiffen the heart muscle, reducing the amount of blood the ventricle can hold.
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Increase the risk of arrhythmias (irregular heartbeats).
Even if you don’t feel symptoms right away, HCM can silently strain your heart. That’s why ongoing monitoring is vital.
What You Can Do Next
If you or a loved one has been diagnosed with HCM:
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Talk to your doctor about genetic testing and family screening.
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Ask if you should see a cardiologist who specializes in inherited heart disease.
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Share information with your relatives — especially if they’re experiencing unexplained chest pain, dizziness, or shortness of breath.
For Black patients, pushing for thorough evaluation and second opinions when necessary can be lifesaving. Don’t be afraid to advocate for yourself and your family.
