title: A Novel Germline Mutation in Exon 15 of the APC Gene in Attenuated Familial Adenomatous Polyposis: A Report of Two Cases.
abstract: Attenuated familial adenomatous polyposis (AFAP) is a variant of familial adenomatous polyposis with fewer than one hundred colorectal polyps and a later age of onset of the cancer. Here, we report two cases of AFAP within family members. Each patient demonstrated the same novel germ line mutation in exon 15 of the adenomatous polyposis coli (APC) gene and was successfully managed with sulindac after refusal to perform colectomy: a 23-year-old man with incidentally diagnosed gastric adenoma and fundic gland polyps underwent colonoscopy, and fewer than 100 colorectal polyps were found; a 48-year-old woman who happened to be the mother of the 23-year-old man also showed fewer than 100 colorectal polyps on colonoscopy. Genetic analysis revealed a novel frameshift mutation in exon 15 of the APC gene. The deletion of adenine-guanine with the insertion of thymine in c.3833-3834 resulted in the formation of stop codon 1,287 in both patients. The patients were treated with sulindac due to their refusal to undergo colectomy. The annual follow-up upper endoscopy and colonoscopy in the following 2 years revealed significant regression of the colorectal polyps in both patients.
authors: Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors: Jaehoon
authors: J
authors: Jahng
authors: Sang Jin
authors: SJ
authors: Yoon
authors: Hyojin
authors: H
authors: Park
keywords: APC; Attenuated familial adenomatous polyposis; Exon 15; Mutation