Genetic Testing for FAP

Emily Malcolm, PhD avatar

by Emily Malcolm, PhD |

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FAP and genetic testing

Genetic testing is a medical procedure that can determine whether you have changes in your genes or chromosomes that could cause disease.

This type of testing is voluntary, and helps to identify diseases before symptoms appear. Such early identification can, for a number of diseases including FAP, be key to slowing their progression.

Genetics of FAP

Familial amyloid polyneuropathy (FAP) is a rare progressive disease characterized by the buildup of amyloids — misfolded proteins — that interfere with tissue and organ function. Mutations in the TTR gene cause FAP, as they result in the protein that the gene encodes being made incorrectly. Cells cannot clear the misfolded protein as they should, and it accumulates.

Doctors use genetic testing to confirm a FAP diagnosis. If someone in your family has FAP, you may want to talk to a genetic counselor to help you determine whether you should have a genetic test.

How is genetic testing done?

Your doctor will arrange for you to give a blood sample at a local clinic or hospital. Some hospitals can perform genetic testing in-house, but most are done at independent laboratories. The laboratory will take your blood sample, isolate DNA from it, and determine if you have a known mutation for the disease that your doctor suspects.

A laboratory report with test results will be sent to your doctor. Your doctor will then meet with you to explain the results of your genetic test. If the test is positive for FAP, your doctor may want to run additional tests before discussing treatment options.

Are there any risks or drawbacks?

The process of giving blood for a genetic test has few risks; similar to any other blood draw, there is a risk of bleeding, infection, or bruising around the needle injection site. Some people may feel lightheaded or dizzy after a blood draw.

Some people may not want to know whether they have a genetic disease, especially if treatment options are limited. Moreover, a positive genetic test doesn’t necessarily tell you whether you will develop symptoms, how quickly the disease will progress, or how severe the disease will be for you.

You may want to talk to a genetic counselor prior to getting a genetic test. A counselor can ably inform you about the potential benefits and drawbacks of testing outcomes.


Last updated: May 28, 2020


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.