TY - JOUR T1 - Gastric polyposis and desmoid tumours as a new familial adenomatous polyposis clinical variant associated with <em>APC</em> mutation at the extreme 3′-end JF - Journal of Medical Genetics JO - J Med Genet DO - 10.1136/jmedgenet-2019-106299 SP - jmedgenet-2019-106299 AU - Vittoria Disciglio AU - Candida Fasano AU - Filomena Cariola AU - Giovanna Forte AU - Valentina Grossi AU - Paola Sanese AU - Martina Lepore Signorile AU - Nicoletta Resta AU - Claudio Lotesoriere AU - Alessandro Stella AU - Ivan Lolli AU - Cristiano Simone Y1 - 2019/10/04 UR - http://jmg.bmj.com/content/early/2019/10/04/jmedgenet-2019-106299.abstract N2 - Germline mutations of the APC gene, which encodes a multidomain protein of 2843 amino acid residues, cause familial adenomatous polyposis (FAP). Three FAP clinical variants are correlated with the location of APC mutations: (1) classic FAP with profuse polyposis (&gt;1000 adenomas), associated with mutations from codon 1250 to 1424; (2) attenuated FAP (&lt;100 adenomas), associated with mutations at APC extremities (before codon 157 and after codon 1595); (3) classic FAP with intermediate colonic polyposis (100–1000 adenomas), associated with mutations located in the remaining part of APC. In an effort to decipher the clinical phenotype associated with APC C-terminal germline truncating mutations in patients with FAP, after screening APC mutations in one family whose members (n=4) developed gastric polyposis, colon oligo-polyposis and desmoid tumours, we performed a literature meta-analysis of clinically characterised patients (n=97) harbouring truncating mutations in APC C-terminus. The APC distal mutations identified in this study cluster with a phenotype characterised by colon oligo-polyposis, diffuse gastric polyposis and desmoid tumours. In conclusion, we describe a novel FAP clinical variant, which we propose to refer to as Gastric Polyposis and Desmoid FAP, that may require tailored management. ER -