Hereditary ATTR amyloidosis is a genetic condition that is currently classified as a rare disease. It occurs when there is a change in the transthyretin (TTR) gene, which provides instructions for making the transthyretin protein.
This protein normally helps carry vitamin A and thyroid hormone through the bloodstream. When certain changes occur in the TTR gene, the protein can become unstable and fold incorrectly. Over time, these unstable proteins can form amyloid deposits that build up in organs and tissues.
These deposits most often affect the heart and the peripheral nerves, although other parts of the body may also be involved.
How Hereditary ATTR Affects the Body
Amyloid deposits can affect different organs depending on where they build up.
When amyloid accumulates in the heart, it can cause the heart muscle to become stiff. This condition is known as cardiomyopathy and may lead to symptoms such as fatigue, shortness of breath, or swelling in the legs.
When amyloid affects the nerves, it can lead to peripheral neuropathy, which may cause symptoms such as numbness, tingling, weakness, or problems with balance.
Because these symptoms often resemble more common health conditions, hereditary ATTR amyloidosis has historically been underrecognized.
Hereditary vs. Other Forms of Amyloidosis
There are several types of amyloidosis. Some forms are not inherited and occur when proteins produced by the body accumulate for other reasons.
Hereditary ATTR amyloidosis is different because it is caused by a genetic change that can be passed from one generation to the next. A person who carries a TTR gene variant may pass that risk on to their children even if they do not become ill themselves.
For this reason, understanding family health history and genetic testing can play an important role in recognizing hereditary disease.
Understanding TTR Gene Variants
Changes in a gene are often called variants. A genetic variant simply means there is a small difference in the gene’s code.
Many genetic variants do not affect health. Others can change how a protein behaves in the body.
Certain variants in the TTR gene can cause the transthyretin protein to become unstable, which allows amyloid deposits to form over time.
One variant known as V122I has been identified in some individuals with West African ancestry and is associated with hereditary ATTR amyloidosis that primarily affects the heart.
Why Awareness and Family History Matter
Hereditary ATTR amyloidosis has often gone unrecognized because its symptoms can develop slowly and may resemble more common health conditions. As a result, many people may experience symptoms for years before the underlying cause is identified.
Because hereditary ATTR amyloidosis is passed through families, patterns of illness may sometimes appear across generations. In some families, relatives may have experienced heart problems, nerve symptoms, or other health issues without realizing they were connected.
Understanding family health history can help individuals recognize possible signs of hereditary disease and begin conversations with healthcare providers about whether further evaluation or genetic testing may be appropriate.
Increasing awareness also helps families share important health information across generations so that future family members are better informed about potential risks.
What Is Hereditary ATTR Amyloidosis?
Understanding the Language of Amyloidosis
Medical information can sometimes include unfamiliar words.
Below are a few key terms that may help make hereditary amyloidosis easier to understand.
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Amyloid refers to proteins that have folded incorrectly and clumped together. Over time, these proteins can form deposits in organs and tissues, which may interfere with normal organ function.
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Transthyretin is a protein made mainly in the liver. Its normal role is to help carry vitamin A and thyroid hormone through the bloodstream.
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A gene is a segment of DNA that provides instructions for how the body makes proteins and carries out many functions.
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A genetic variant is a small difference in a gene’s code. Many variants do not affect health, but some can change how proteins behave in the body.
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Hereditary means a condition that can be passed down through families from one generation to the next.
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V122I is a specific variant of the transthyretin gene. It has been identified in some individuals with West African ancestry and is associated with hereditary ATTR amyloidosis that primarily affects the heart.
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Peripheral neuropathy refers to damage to nerves outside the brain and spinal cord. It may cause symptoms such as numbness, tingling, weakness, or problems with balance.
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Cardiomyopathy refers to disease of the heart muscle. In amyloidosis, amyloid deposits can make the heart muscle stiff and affect how well it pumps blood.
Awareness often begins with a conversation … within families, communities, and across generations.