Familial amyloid polyneuropathy (FAP) is a progressive disease in which patients experience severe peripheral neuropathy, cardiac dysfunction, infections, and cachexia (extreme weight loss and muscle wasting).

The life expectancy of TTR-FAP patients is about 10 years after diagnosis. The progression of the disease can vary among early- and late-onset patients — with early-onset patients, whose symptoms appear between 30 and 50 years old, usually experiencing more rapid disease progression. Disease progression is reportedly slower with a survival rate of up to 20 years among patients who develop symptoms later, after 50.

Factors affecting life expectancy

FAP is caused by mutations in the TTR gene, which encodes for a protein that’s responsible for transporting a hormone called thyroxine and vitamin A throughout the body.

A mutant TTR gene generates a misfolded TTR protein, which forms insoluble protein deposits called amyloids in the heart, nervous system, eyes, and other tissues.

Nearly 130 different FAP-related TTR gene mutations have been identified, with the most common being the so-called Val30Met mutation where the amino acid methionine substitutes the amino acid valine. (Amino acids are building blocks of proteins).

Life expectancy of FAP patients depends on the type of TTR mutation, organ(s) affected by the disease, and how early a person is diagnosed and treated.

Treatment options

Although no medications can reverse the damage caused by amyloid deposits, there are several experimental and approved treatments to slow the build-up of amyloids in the nervous system and other body parts, and thereby delay disease progression and improve the life expectancy of patients.

These include medications such as Vyndaqel (tafamidis), Dolobid (diflunisal), Tegsedi (inotersen), and Onpattro (patisiran). The effectiveness of these treatments depends on the patient’s disease progression at diagnosis.

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FAP 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 providers 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.