5 answers about ATTR amyloidosis

Amyloidosis is a group of conditions that occur when clumps of proteins accumulate throughout the body. These clumps of proteins are called amyloid deposits, and when they become too large or too numerous, they can disrupt the organs and tissues where they have accumulated.

Transthyretin amyloidosis (ATTR amyloidosis) is a type of amyloidosis related to the buildup of a protein called transthyretin (TTR). Here are five answers to know about this condition.

Are there different types of ATTR amyloidosis?

Yes. There are two types of ATTR amyloidosis:

• Hereditary ATTR amyloidosis involves an inherited genetic mutation that causes the body to produce abnormal versions of the TTR protein. These abnormal TTR proteins can accumulate to form amyloid deposits. This type most often affects the nervous system, though it can also affect the eyes and other organs.
• Wild-type ATTR amyloidosis is an age-related disease that typically occurs in people who are over the age of 65. It involves normal TTR proteins and does not involve a genetic mutation. The normal TTR proteins accumulate to form amyloid deposits in the heart tissue (though it can also affect the nervous system).

What parts of the body are affected by ATTR amyloidosis?

Sometimes ATTR amyloidosis is categorized based on the primary tissues and organs that it affects:

• ATTR cardiomyopathy (ATTR-CM) involves amyloid deposits that accumulate in the tissues of the heart. However, some people who have this type also experience problems with the peripheral nervous system.
• Neuropathic ATTR involves amyloid deposits that accumulate in the nervous system. This usually refers to the peripheral nervous system, the parts of the nervous system outside of the brain and spinal cord (which make up the central nervous system). The peripheral nervous system includes the autonomic nervous system, which controls involuntary functions like breathing, heartbeat, blood pressure, digestion, and sexual arousal.
• There is also a subtype of hereditary ATTR amyloidosis called leptomeningeal ATTR that involves the central nervous system. It occurs when amyloid deposits accumulate in thin layers of tissue (called the leptomeninges) that protect the brain and spinal cord. This type is less common than ATTR that involves the peripheral nervous system or cardiac tissue.

What are the symptoms of ATTR amyloidosis?

The symptoms of ATTR amyloidosis depend on the tissues and organs involved:

• Amyloidosis that involves the heart can cause irregular heartbeat, shortness of breath, reduced exercise capacity, and sudden drops in blood pressure.
• Amyloidosis that involves the nervous system can cause peripheral neuropathy—numbness, tingling, and muscle weakness in the limbs and extremities. It can also cause problems with digestion, bowel and bladder control, sexual function, kidney function, and the eyes.
• Leptomeningeal involvement can lead to stroke, brain bleeds, seizures, dementia, movement disorders, and eye problems.

It’s important to note that the symptoms of ATTR amyloidosis overlap with other types of amyloidosis. ATTR amyloidosis also shares symptoms with many other health conditions. Symptoms should always be evaluated by a healthcare provider.

What are the treatment options for ATTR amyloidosis?

Treatment will depend on the type of ATTR amyloidosis, the organs and systems involved, and how far the disease has progressed. Because transthyretin (the protein that forms amyloid deposits in ATTR amyloidosis) is made in the liver, a liver transplant may be recommended for some patients.

There are also several medications that are approved to treat ATTR amyloidosis:

• TTR stabilizers. These drugs prevent the transthyretin protein from forming amyloid deposits.
• Gene silencers. These drugs block the production of the abnormal transthyretin protein by blocking the gene responsible for the production of that protein.

Different drugs are approved for the treatment of neuropathic ATTR and cardiac ATTR, and different drugs are approved for the treatment of hereditary ATTR and wild-type ATTR. Additional therapies are under development. If you or a loved one is living with a form of ATTR amyloidosis, a healthcare provider will be your best source of information about treatment.

What healthcare providers treat ATTR amyloidosis?

The treatment of ATTR amyloidosis usually involves a multidisciplinary team made up of different healthcare providers with different specialties. This can include medical doctors who specialize in conditions that affect the heart, nervous system, eyes, kidneys, and more. Genetic counseling is also recommended.

A care team can include providers that specialize in supportive care, which is another important aspect of treatment. Supportive care can include things like physical therapy, nutrition therapy, and other therapies to improve quality of life while living with ATTR amyloidosis.