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.