The main sign of FAP is hundreds or even thousands of polyps growing in your colon and rectum, usually starting by your mid-teens. The polyps are nearly 100 percent certain to develop into colon cancer or rectal cancer by the time you're in your 40s. Causes Familial adenomatous polyposis is caused by a defect in a gene that's usually inherited from a parent. But some people develop the abnormal gene that causes the condition. Risk factors Your risk of familial adenomatous polyposis is higher if you have a parent, child, brother, or sister with the condition.                   Complications In addition to colon cancer, familial adenomatous polyposis can cause other complications:  Duodenal polyps. These polyps grow in the upper part of your small intestine and may become cancerous. But with careful monitoring, duodenal polyps can often be detected and removed before cancer develops. Periampullary polyps. These polyps occur where the bile and pancreas ducts enter the duodenum (ampulla). Periampullary polyps might become cancerous but can often be detected and removed before cancer develops. Gastric fundic polyps. These polyps grow in the lining of your stomach. Desmoids. These noncancerous masses can arise anywhere in the body but often develop in the stomach area (abdomen). Desmoids can cause serious problems if they grow into nerves or blood vessels or exert pressure on other organs in your body. Other cancers. Rarely, FAP can cause cancer to develop in your thyroid gland, central nervous system, adrenal glands, liver or other organs. Noncancerous (benign) skin tumors. Benign bone growths (osteomas). Congenital hypertrophy of the retinal pigment epithelium (CHRPE). These are benign pigment changes in the retina of your eye. Dental abnormalities. These include extra teeth or teeth that don't come in. Low numbers of red blood cells (anemia).  Prevention Preventing FAP is not possible, since it is an inherited genetic condition. However, if you or your child is at risk of FAP because of a family member with the condition, you will need genetic testing and counseling. If you have FAP, you will need regular screening, followed by surgery if needed. Surgery can help prevent the development of colorectal cancer or other complications. By Mayo Clinic Staff By Mayo Clinic Staff  Familial adenomatous polyposis care at Mayo Clinic 
sign fap hundreds thousands polyps growing colon rectum  starting mid-teens  polyps nearly 100 percent develop colon cancer rectal cancer time you're 40s  causes familial adenomatous polyposis caused defect gene that's inherited parent  people develop abnormal gene causes condition  risk factors risk familial adenomatous polyposis higher parent  child  brother  sister condition                    complications addition colon cancer  familial adenomatous polyposis can cause complications:  duodenal polyps  polyps grow upper part small intestine may cancerous  careful monitoring  duodenal polyps can detected removed cancer develops  periampullary polyps  polyps occur bile pancreas ducts enter duodenum (ampulla)  periampullary polyps cancerous can detected removed cancer develops  gastric fundic polyps  polyps grow lining stomach  desmoids  noncancerous masses can arise body develop stomach area (abdomen)  desmoids can cause problems grow nerves blood vessels exert pressure organs body  cancers  rarely  fap can cause cancer develop thyroid gland  central nervous system  adrenal glands  liver organs  noncancerous (benign) skin tumors  benign bone growths (osteomas)  congenital hypertrophy retinal pigment epithelium (chrpe)  benign pigment changes retina eye  dental abnormalities  include extra teeth teeth don't come in  low numbers red blood cells (anemia)   prevention preventing fap possible  inherited genetic condition  however  child risk fap family member condition  will need genetic testing counseling  fap  will need regular screening  followed surgery needed  surgery can help prevent development colorectal cancer complications  mayo clinic staff mayo clinic staff  familial adenomatous polyposis care mayo clinic 
familial adenomatous polyposis