ATTR-CM in Black Americans: Why it still continues to be underdiagnosed

For some Black Americans, heart failure symptoms may be linked to an underlying inherited condition called hereditary transthyretin amyloid cardiomyopathy (hATTR-CM or hereditary ATTR-CM).

Because hereditary ATTR-CM in Black people can resemble more common heart conditions, it may go unrecognized for years. Learning how the disease may appear, what family history can reveal, and when to ask about testing may help you get clearer answers sooner.

What is the V122I mutation?

ATTR-CM develops when the protein transthyretin (TTR) becomes unstable and loses its normal four-protein structure. Instead, the protein dissociates into individual units that are prone to misfold and form clumps called amyloid deposits. Over time, these deposits accumulate in the heart, stiffening the heart walls and making it more difficult for the heart to pump blood as the disease progresses.

ATTR-CM has two main causes. In wild-type ATTR-CM, the protein becomes unstable due to age-related processes. In contrast, hereditary ATTR-CM arises from mutations in the TTR gene, which codes for the transthyretin protein, that are usually passed down through families.

Hereditary ATTR-CM appears to be disproportionately more common among Black Americans compared with other racial or ethnic groups, largely because of the higher prevalence of a specific TTR gene mutation called V122I.

The TTR V122I mutation, also called the Val122Ile mutation, is the most common cause of hereditary ATTR-CM in the U.S. About 4% of Black Americans carry this variant, although not everyone who carries it will develop ATTR-CM.

Why ATTR-CM may be underrecognized in Black Americans

ATTR-CM in African Americans can resemble more common heart problems. It may be mistaken for heart failure caused by high blood pressure or thickening of the heart muscle from other causes.

According to the American Heart Association, ATTR-CM may be misdiagnosed in part because symptoms may be mild or hard to notice at first.

However, delays in recognizing amyloidosis in African Americans go beyond clinical presentation. Access to care, awareness, cost, and mistrust in the healthcare system can all affect how quickly someone gets the correct diagnosis and treatment.

These barriers may make Black patients more likely to be diagnosed at later stages of disease progression, when the heart has already been significantly affected, and lead to worse outcomes.

Symptoms and red flags that should not be overlooked

ATTR-CM symptoms might be easy to explain away or ignore at first. For example, you might feel more tired than usual, feel short of breath during a short walk, or notice swelling in your feet or ankles.

Other possible symptoms may include:

belly bloating
confusion
a fast heartbeat
abnormal heart rhythms (arrhythmia)

Some red flags may also appear years before heart symptoms do. Tell your doctor if you have heart failure and a history of any of the following:

Carpal tunnel syndrome, especially in both wrists
Spinal stenosis (narrowing around the spine)
Spontaneous bicep tendon ruptures (a tear in the tendon)
Numbness, tingling, or nerve pain in the hands or feet
Dizziness when standing

When family history and genetic testing matter

Family history can be an important clue in detecting hereditary ATTR-CM. Tell your doctor if a parent, sibling, or close relative had heart failure, thickened heart muscle, or unexplained heart problems later in life.

Genetic testing may help reveal whether you carry a TTR gene mutation and determine whether hereditary ATTR-CM is involved. According to the American College of Cardiology, genetic testing is warranted after an ATTR-CM diagnosis to determine whether the disease is hereditary or wild-type.

Barriers to early diagnosis and care

Even when ATTR-CM is suspected, getting answers can still take time. Some people may not live near an amyloidosis center or a doctor who regularly treats ATTR-CM. Cost, insurance requirements, transportation, and taking time off work can make follow-up more difficult.

Research has found that Black patients are often less likely than white patients to receive pyrophosphate imaging, a common heart scan used to help diagnose ATTR-CM. Black people with lower socioeconomic status also seem to have worse outcomes than white people, even when diagnosed at similar stages of the disease.

How community awareness can help people get diagnosed sooner

When more people in the community know about the risk of ATTR-CM, they may be more likely to speak up when something feels off. That might mean making sure you know your family’s heart health history, talking to a doctor about whether symptoms could be more than just age-related, or inquiring about genetic testing.

Early recognition of ATTR-CM is essential to delay disease progression and improve long-term outcomes. If you are of African descent and notice symptoms or have a family history of unexplained heart problems, talk with your doctor about whether additional testing may be appropriate.

Amyloidosis News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.