CPT® Code 81202

APC (adenomatous polyposis coli) (eg, familial adenomatosis polyposis [FAP], attenuated FAP) gene analysis; known familial variants

The CPT® Code 81202 pertains to the molecular genetic testing of the adenomatous polyposis coli (APC) gene, specifically focusing on known familial variants. This testing is crucial for individuals who may be at risk for familial adenomatosis polyposis (FAP), a hereditary condition characterized by the development of numerous polyps in the colon and rectum, which can lead to colorectal cancer if not monitored and managed appropriately. FAP is inherited in an autosomal dominant manner, meaning that a single mutated copy of the APC gene inherited from one parent is sufficient to cause the disease. The classic form of FAP is typically more severe than its attenuated counterpart, with the former leading to a higher number of polyps and an earlier onset of colorectal cancer. The APC gene plays a vital role as a tumor suppressor, and mutations in this gene disrupt its function, resulting in uncontrolled cell growth and polyp formation. The gene is located on chromosome 5, and over 700 distinct mutations have been identified, many of which result in a truncated, nonfunctional APC protein. Testing for known familial variants, as indicated by CPT® Code 81202, is essential for identifying specific mutations that may have been passed down through families, including those associated with conditions such as Turcot syndrome and the I1307K variant prevalent in the Ashkenazi Jewish population, both of which are linked to an increased risk of colorectal cancer.