HCM, a family story ?
HCM is often an inherited condition, which means it can affect more than one person within the same family. When you are diagnosed, it may raise important questions for your parents, siblings, children, and other relatives.
Identifying cardiomyopathy and finding the cause at an early stage can be crucial in saving lives. By responding quickly, we can put in place strategies to reduce the risk of complications and improve patient life expectancy and quality of life.
Professor Antoine Bondue
CARDIOLOGIST AT THE UNIVERSITY HOSPITAL OF BRUSSELS (ERASMUS HOSPITAL),
AND CHAIR OF THE SCIENTIFIC COMMITTEE OF THE BELGIAN CARDIOLOGY LEAGUE.
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Is HCM hereditary?
Up to 60% of patients with hypertrophic cardiomyopathy (HCM) carry inherited genetic variants that cause the disease, but many are unaware of it[21]. If a person carries such a variant, there is a 50/50 chance of passing it on to their children.[22]
This means that a diagnosis can have implications for family members, who could develop HCM symptoms over time. It is therefore recommended that close relatives (parents, siblings and children) should also be examined by a cardiologist. In some cases, genetic testing can help to figure out what variant, if any, is responsible for HCM in a family.
What does this means for my family?[23]
Because HCM can run in families, if you have been diagnosed with HCM, your first-degree relatives have a significant risk of carrying the HCM genetic mutation. When a pathogenic/likely pathogenic variant has been identified in a patient, it is important to talk about family screening.
The steps to take will depend on the family history of HCM and the results of your genetic test, if you had one. In simple terms:
- Step 1: If you have HCM, genetic testing can help to figure out the gene involved.
- Step 2: If your genetic test is positive, then family members can be tested for the specific gene variant that was found in you.
If you have HCM, your genetic test results will guide next steps for family members.
Q&A
Pregnancy is possible for many people with HCM, but it requires careful planning and specialist support. During pregnancy, the heart faces additional demands: increased blood volume and heart rate, which can worsen symptoms in people with HCM or oHCM, even without treatment considerations. Before planning a pregnancy, it is important to:
- Discuss your individual heart condition with your cardiologist and obstetrician Understand your personal level of risk
- Review any medications you are taking, as some, including cardiac myosin inhibitors, must not be used during pregnancy
- Specialist joint cardiology and obstetric care ('cardiac obstetrics') is recommended for women with significant HCM. Ask your cardiologist whether a referral to a specialist centre is appropriate for you[24].
Screening usually includes:
- Physical examination by a heart doctor
- Thorough checks of the health history
- Electrocardiogram and echocardiogram repeated every 1–3 years in adults (with intervals tailored to each patient), and annually in children and adolescents, even in the absence of symptoms. Follow-up is continued over time, as HCM may develop later in life.
Genetic testing involves:
- Consultation with a genetic counsellor
- Collection of a blood or saliva sample
- Laboratory analysis to identify the gene variant found in the family member
A genetic counsellor can help you understand how HCM is passed down in families, when screening and genetic testing may be needed, and what the results could mean for you and your family.
Genetic counsellors have specific training in genetics and counselling and can help:
- Review the benefits and limitations of genetic testing
- Explain how the test results are interpreted and used
- Support discussions with family members about HCM and the need for screening or testing, even if they feel well
- Identify who in the family should be tested next and which test is most appropriate (for example, if an unaffected family member tests negative, their children may not need to be tested)
Benefits and drawbacks of genetic testing[27]
Potential benefits
- Identifies the underlying cause of HCM in some families
- Helps you and your family members get early monitoring and treatment
- Gives additional information to guide screening and treatment decisions with your healthcare team
- Prevents unnecessary tests, follow-up and worry when someone is found not to have the gene variant
- Helps inform family planning and decisions about having children
Potential drawbacks or challenges
- Learning that you or a family member has HCM can be emotionally difficult and may lead to feelings of sadness, anxiety, guilt or depression
- While some genes are commonly associated with HCM, genetic testing does not always identify a causative variant; some genes have limited evidence of association with HCM, and research in this area is still evolving
How to talk to your family about HCM?[28]
It’s not always easy to talk about inherited conditions, and many parents say they feel guilty about the possibility of passing it on to their children. Your cardiologist, specialist, or genetic counsellor can provide guidance and support.
Mother & daughter
A few years ago, this 21-year-old patient began experiencing heart palpitations, black spots in her vision, and a loss of strength often at the end of a workday or when climbing stairs. She quickly realized something was wrong and consulted a doctor, who detected a heart murmur. Further tests later confirmed the diagnosis of obstructive hypertrophic cardiomyopathy (HCM).
The diagnosis also shed light on her family history: years earlier, her grandfather had died from a heart condition that was never clearly identified. Only with her diagnosis did the family understand what had been affecting them across generations.
Discover her journey and learn why awareness and family genetic screening can make all the difference.
Patient experiences
Discover real stories from people living with HCM.
Resource Hub
Find additional resources, documents, and reliable information about HCM.
[21] Ommen SR et al. Circulation. 2024;149(23):e1239-e1311. Correction published in Circulation. 2024;150(8):e198. doi: 10.1161/CIR.0000000000001277
[22] HCM Family Screening and Genetic Testing: What You Need to Know. (s. d.). CardioSmart. https://www.cardiosmart.org/assets/fact-sheet/hcm-family-screening-and-genetic-testing-what-you-need-to-know
[23] HCM Family Screening and Genetic Testing: What You Need to Know. (s. d.). CardioSmart. https://www.cardiosmart.org/assets/fact-sheet/hcm-family-screening-and-genetic-testing-what-you-need-to-know
[24] European Heart Journal, Volume 44, Issue 37, 1 October 2023, Pages 3503–3626, https://doi.org/10.1093/eurheartj/ehad194
[25] HCM Family Screening and Genetic Testing: What You Need to Know. (s. d.). CardioSmart. https://www.cardiosmart.org/assets/fact-sheet/hcm-family-screening-and-genetic-testing-what-you-need-to-know
[26] HCM Family Screening and Genetic Testing: What You Need to Know. (s. d.). CardioSmart. https://www.cardiosmart.org/assets/fact-sheet/hcm-family-screening-and-genetic-testing-what-you-need-to-know
[27] HCM Family Screening and Genetic Testing: What You Need to Know. (s. d.). CardioSmart. https://www.cardiosmart.org/assets/fact-sheet/hcm-family-screening-and-genetic-testing-what-you-need-to-know
[28] HCM Family Screening and Genetic Testing: What You Need to Know. (s. d.). CardioSmart. https://www.cardiosmart.org/assets/fact-sheet/hcm-family-screening-and-genetic-testing-what-you-need-to-know