Cece, living with hATTR amyloidosis


Understanding Hereditary ATTR Amyloidosis

Hereditary ATTR (hATTR) amyloidosis is an inherited, progressive disease caused by a genetic mutation that results in the misfolding of transthyretin (TTR) proteins. This results in the formation of amyloid fibrils that could deposit in the nerves, heart, and/or gastrointestinal (GI) tract.

hATTR amyloidosis affects approximately 50,000 people worldwide. Many people remain undiagnosed or misdiagnosed.

How does hATTR amyloidosis affect the body?

People with hATTR amyloidosis have a genetic mutation that prevents TTR protein, which is made in the liver, from having its normal structure. Instead, TTR misfolds and accumulates as amyloid deposits in the body—in the heart, nerves, and GI tract, as well as other organs—causing debilitating symptoms.

Symptoms associated with this condition

hATTR amyloidosis symptoms can vary from person to person, depending on which organs or tissues are affected, and can worsen as the disease progresses. Symptoms may include:

  • Loss of sensation, limb weakness and pain
  • Alternating episodes of diarrhea, constipation, nausea, and vomiting
  • Heart-related issues


For a complete list of symptoms, see the hATTR amyloidosis Backgrounder below.

Learn more about hATTR amyloidosis

Download the Alnylam hATTR amyloidosis Backgrounder.

This is one family’s story

“Amyloidosis has kind of been the black cloud over my family.” – Tonya, family living with hATTR amyloidosis

Know Your Family History


The BridgeTM is a program designed to help raise awareness of hereditary ATTR (hATTR) amyloidosis and promote education on the condition for patients and their families.

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Alnylam Act provides no-charge, independent genetic testing and counseling to individuals in the US and Canada who may have hATTR amyloidosis.

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Alnylam Assist® offers patients personalized support throughout their treatment with an Alnylam product.

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Learn more about our FDA-approved therapies.

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