Familial adenomatous polyposis (FAP) is a genetic disease. It affects the colon and causes over 100 adenomatous polyps to form. These growths significantly increase the risk of colorectal and other cancers in body areas like the stomach and pancreas.
People with FAP might notice extra symptoms besides polyps. These can include benign bone tumors, extra teeth, and changes in the eyes or skin. The disease also comes in different forms, each with its unique set of symptoms and cancer risks.
Tumors and other issues in FAP link back to a gene called APC. This gene’s changes are passed down in families and cause polyps to develop. A test for these genes can help doctors confirm FAP and its specific type.
Treating FAP needs a combined effort from different medical areas. Surgery to remove the colon, or colectomy, is a common step to lower cancer risk. Alongside surgery, careful watch, medicine, and new treatments like stem cells are being studied to help manage FAP.
Key Takeaways:
- FAP is a genetic condition characterized by the development of multiple adenomatous colon polyps.
- FAP can elevate the risk of colorectal cancer and cancer in other organs.
- Additional symptoms of FAP may include osteomas, extra teeth, CHRPE, and non-cancerous skin changes.
- FAP has subtypes with different clinical features and associated tumor types.
- FAP is caused by genetic alterations in the APC gene and is inherited in an autosomal dominant manner.
- Colectomy is a common treatment for FAP, aiming to remove polyps and reduce the risk of colorectal cancer.
- Stem cell therapy is an area of ongoing research for FAP treatment.
Diagnosis and Inheritance of FAP
Familial adenomatous polyposis (FAP) is diagnosed when someone has over 100 adenomatous colon polyps. Genetic tests confirm this, showing changes in the APC gene related to FAP.
If a person with FAP has kids, there’s a 50% chance they’ll pass it on. But, not everyone with FAP has a family history of the disease. Some get it because of new changes in the APC gene, not from their parents.
Colorectal polyposis can also come from changes in the MUTYH gene, causing MUTYH-associated Polyposis (MAP). A full genetic test can look for changes in many genes linked to polyp growth, giving a clearer picture of the genetic causes.
Genetic testing is key in both diagnosing FAP and pinpointing the exact genetic issues involved.
APC Gene Alterations and FAP
The APC gene keeps cell growth in check. When it’s mutated, too many colon polyps form. Testing for these mutations helps diagnose and treat FAP.
MUTYH Gene Alterations and MAP
MUTYH repairs DNA. Mutations in this gene increase polyp risk and the chance of colon cancer. Finding these mutations can lead to a diagnosis of MAP.
Knowing about the genetic aspects of FAP and its versions helps doctors give the right treatments. This improves the lives of those with these conditions.
Treatment and Prevention of FAP
Familial adenomatous polyposis (FAP) needs a full approach to treatment and prevention. The main treatment is colectomy. This surgery removes part or all of the colon. It’s done to lower the risk of polyps and colorectal cancer. By doing this, the chance of cancer in the colon gets a lot lower.
After colectomy, doctors might suggest taking sulindac to deal with any remaining rectal polyps. It’s very important to keep an eye out for cancer or pre-cancerous growths. This is where surveillance comes in. It includes regular clinical and endoscopic checks. They are key for early warning signs of cancer. With these checks, doctors can act quickly to treat any issues found.
Sometimes, those with FAP might also need to remove duodenal polyps to avoid duodenal cancer. Even though desmoid tumors are not cancerous, they need to be watched. In some cases, they might require surgery, medicine, chemotherapy, or radiation. What treatment is needed depends on how serious the tumor is and where it’s located.
When it comes to FAP, preventing issues is very important. This means getting regular checks to catch any tumors early. Genetic counseling can help family members understand their risks. It also can help them make wise health choices. If a couple is thinking about having kids and one of them has the FAP gene, they have options. Preimplantation genetic diagnosis (PGD) offers a way to test embryos before implantation.
Scientists are also looking into new ways to prevent FAP, like using certain medications as a type of shield. This ongoing research aims to improve how we control FAP over time.