How do I know if I have Familial Adenomatous Polyposis?

Familial Adenomatous Polyposis (FAP) is typically identified through genetic testing for mutations in the APC gene or by the discovery of numerous colorectal polyps during a colonoscopy. Because FAP is an inherited condition, the most reliable way to know if you are at risk is by reviewing your family medical history for early-onset colon cancer or multiple polyps.

What are the early signs and symptoms of Familial Adenomatous Polyposis?

In its early stages, Familial Adenomatous Polyposis is often asymptomatic, which is why proactive screening is essential. As the number of polyps increases, you may experience subtle warning signs. Common indicators that warrant a conversation with your physician include:

• Unexplained changes in bowel habits (persistent diarrhea or constipation).


• Blood in the stool or rectal bleeding.


• Unexplained abdominal pain or cramping.


• Unintended weight loss or fatigue related to iron-deficiency anemia.

When should I seek medical evaluation for Familial Adenomatous Polyposis?

If you have a known family history of Familial Adenomatous Polyposis, you should consult a gastroenterologist or a genetic counselor immediately, even if you feel healthy. If you do not have a known family history but experience persistent digestive irregularities, ask your doctor for a referral to a specialist. When speaking with your doctor, use the specific term "Familial Adenomatous Polyposis" and provide a detailed family tree, noting any relatives who were diagnosed with colon cancer before age 50.

Which diagnostic tests are used to confirm Familial Adenomatous Polyposis?

The definitive diagnosis for Familial Adenomatous Polyposis involves two primary approaches:

1. Genetic Testing: A blood test to identify a germline mutation in the APC gene.


2. Colonoscopy: A visual examination of the colon to count the number of polyps; the presence of more than 100 adenomatous polyps is a clinical hallmark of classic FAP.

What are the red flags requiring urgent care?

Seek medical attention immediately if you experience severe, unrelenting abdominal pain, a complete change in bowel obstruction patterns, or significant rectal bleeding. These symptoms require urgent evaluation to rule out malignant transformation, which is a major risk in untreated Familial Adenomatous Polyposis.

Next steps

• Schedule a consultation with a genetic counselor to discuss your family history.


• Request a referral to a gastroenterologist specializing in hereditary gastrointestinal cancer syndromes.


• Connect with the 147 members of the DiseaseMaps.org Familial Adenomatous Polyposis community to share experiences and find support.

Medical disclaimer: This information is for educational purposes only and does not replace professional medical advice, diagnosis, or treatment.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Familial Adenomatous Polyposis.


• Orphanet: Familial Adenomatous Polyposis (ORPHA:733).


• OMIM (Online Mendelian Inheritance in Man): Adenomatous Polyposis of the Colon (Entry #175100).


• The Colon Cancer Foundation: Educational resources on hereditary syndromes.