Up to 25% of FAP cases result from de novo APC mutations, meaning these patients do not have a family history of FAP but remain at risk of transmitting the disease to their offspring [14]. In this case, genetic testing confirmed the presence of a pathogenic variant in the APC gene (c.3183_3187delACAAA p.(Gln1062*)), consistent with a diagnosis of FAP. The gene discussed is APC; the disease is Familial adenomatous polyposis.