Key takeaways

  • Hereditary ATTR-CM is a genetic condition where mutated TTR genes cause unstable TTR proteins to form amyloid proteins, which can accumulate in the heart and impair its function.
  • If a parent has a TTR gene mutation, there is a 50% chance their children will inherit it, though not everyone with the mutation develops symptoms. Genetic testing and counseling can help assess risk.
  • Early detection through genetic testing can lead to timely monitoring and treatment with medications that may slow the progression of hATTR-CM and improve quality of life, even though there is currently no cure.

Hereditary ATTR-CM (hATTR-CM) is a serious and often underdiagnosed medical condition in which abnormal proteins to build up in specific parts of the body.

When these proteins accumulate in the heart’s left ventricle, they can make it harder for the heart to pump blood throughout the body.

Symptoms and disease progression can vary from person to person. If one of your parents has received an ATTR-CM diagnosis, you have a 50% chance of inheriting the gene variant associated with the condition.

Hereditary ATTR-CM is caused by a genetic mutation in the transthyretin (TTR) gene.

This gene is responsible for sending signals that lead to the creation of TTR proteins. When the gene mutates, the resulting TTR proteins can become unstable and form abnormal clusters, known as amyloid proteins, in parts of the body where they don’t typically belong.

When amyloid proteins build up in the heart muscle, it can cause the heart walls to become thick and stiff. This stiffness makes it harder for the heart to pump blood effectively throughout the body.

Hereditary ATTR-CM is autosomal dominant. This means that the TTR gene mutation from just one affected parent results in a 50% chance that each child will inherit the same mutation. However, not everyone who inherits the gene mutation will go on to develop symptoms.

Researchers have identified more than 100 different types of TTR mutations. The variations differ geographically. In the U.S., the most common mutation is ATTR V122I, which occurs in about 3% to 4% of African Americans.

Other common variants include:

  • ATTR V30M, found mainly in people from or with ancestry linked to:
    • Portugal
    • Spain
    • France
    • Sweden
    • Japan
    • descendants from all of these regions
  • ATTR T60A, which is more common in people of Irish descent and is the most frequently identified variant in the United Kingdom.

You may want to consider genetic testing and counselling for hATTR-CM if an immediate family member, such as a parent, sibling, or child, has been confirmed to carry the gene mutation.

If one of these relatives has the mutation, you have a 50% chance of inheriting it.

You may also consider genetic testing if you experience any of the following symptoms:

  • abnormal heart rhythms
  • shortness of breath
  • swelling in the feet or legs
  • fainting
  • chest congestion
  • numbness or tingling in the hands or feet

You may be at a higher risk for hereditary ATTR-CM if you:

  • have an immediate family member with ATTR-CM or unexplained heart failure
  • are male
  • are African American

Genetic testing for hereditary ATTR-CM often requires minimally invasive sample collection, such as:

  • blood
  • saliva
  • cheek swab

Yes. Even if you don’t have symptoms, it may be worth considering genetic testing if an immediate family member has tested positive for hATTR-CM.

Early testing can help identify risk before symptoms appear and support timely monitoring and care.

While there’s currently no cure for ATTR-CM, medications are available that may help slow disease progression and support quality of life for a longer period.

No. Carrying a TTR gene mutation doesn’t mean you’ll definitely develop hereditary ATTR-CM.

If one of your parents has the mutation, you have a 50% chance of inheriting it. Even if you do inherit the gene variant, symptoms may not develop, or they may appear later in life. A healthcare professional or genetic counselor can help explain what this risk means for you and discuss appropriate monitoring.

Hereditary ATTR-CM is a serious genetic condition in which a mutated gene affects how a specific protein is made. When these abnormal proteins build up in the body, especially in the heart, they can interfere with heart function and may lead to heart failure.

Although some people have a higher genetic risk of hATTR-CM, carrying a family risk doesn’t guarantee that you will inherit the gene or develop the condition.

Genetic testing and counseling can play an important role in early detection and diagnosis and may guide healthcare decisions. Available treatments can help slow disease progression and manage heart-related symptoms.