familial adenomatous polyposis 3

Familial adenomatous polyposis 3, also known as FAP3, is a hereditary condition that primarily affects the colon and other organs of the gastrointestinal system. It is caused by pathogenic variants in the NTHL1 gene, which plays an important role in DNA repair. Affected individuals typically develop multiple adenomatous polyps in the colon, which can predispose them to various cancers over time. Although the onset of polyposis may occur in early adulthood, precise prevalence estimates are not well established due to the rarity of the condition.

The most defining clinical feature of familial adenomatous polyposis 3 is adenomatous colonic polyposis, which is observed in all affected individuals. In addition, many individuals develop cancers such as colon, endometrial, and breast cancer, with some also experiencing pancreatic adenocarcinoma, basal cell carcinoma, duodenal adenocarcinoma, meningioma, or prostate cancer. These features may be identified during routine screenings or following the onset of related clinical symptoms. Not all individuals experience all features, and severity varies considerably between cases.

Familial adenomatous polyposis 3 is associated with variants in the NTHL1 gene, which is involved in the repair of damaged DNA. Disruption of this gene’s normal function increases the risk of developing multiple adenomatous polyps and various malignancies. The condition is inherited in an autosomal recessive manner, meaning that an affected individual must inherit an altered copy of the gene from each parent. This mode of inheritance also suggests that the risk may be higher in families where parents share a common ancestor.

Currently, management of familial adenomatous polyposis 3 focuses on supportive care and symptom management tailored to the individual. Regular surveillance, including colonoscopies and screening for other associated cancers, is a cornerstone of care. A multidisciplinary team, which may include gastroenterologists, oncologists, and genetic counselors, plays a key role in monitoring and managing the condition. Patients are encouraged to discuss all available treatment options with their healthcare team to determine the best approach for their situation.

The outlook for individuals with familial adenomatous polyposis 3 varies widely, depending on factors such as the number of polyps, age at diagnosis, and effectiveness of monitoring and intervention strategies. With current standards of care, many individuals benefit from early detection and proactive management, which can lead to improved quality of life over time. Outcomes described in medical literature continue to evolve as standards of care improve, and severity and symptoms vary widely between individuals. Genetic counseling can provide guidance for families regarding inheritance patterns and appropriate follow-up care.

Clinical trials are underway exploring new treatment approaches for familial adenomatous polyposis 3, with efforts focused on early detection and improved management of polyp development and associated cancers. Individuals interested in clinical trials can search ClinicalTrials.gov or consult their care team for eligibility information.