Familial Adenomatous Polyposis (FAP)

Familial Adenomatous Polyposis (FAP) is a genetic condition that affects the colon and rectum, causing hundreds to thousands of small growths called polyps to develop. These polyps are benign at first but have a very high chance of turning into colorectal cancer if not treated. The condition usually begins to show symptoms in the teenage years or early adulthood. People with FAP may experience symptoms like rectal bleeding, changes in bowel habits, or abdominal pain. Because it affects the digestive system and can lead to cancer, it is considered a serious health issue that requires careful monitoring.

Familial Adenomatous Polyposis (FAP) is an autosomal dominant inherited disorder characterized by the development of hundreds to thousands of adenomatous polyps throughout the colon and rectum. It is caused by germline mutations in the APC tumor suppressor gene, leading to loss of function of the APC protein, which normally regulates cell growth and apoptosis. The unchecked proliferation of colonic epithelial cells results in numerous polyps that have a near 100% risk of progressing to colorectal adenocarcinoma if untreated. Clinically, patients often present with symptoms related to polyp burden such as rectal bleeding, diarrhea, or abdominal pain, typically in adolescence or early adulthood. Extra-colonic manifestations may include desmoid tumors, congenital hypertrophy of the retinal pigment epithelium (CHRPE), and upper gastrointestinal polyps. Early diagnosis and management are critical to prevent malignant transformation and reduce morbidity and mortality.