MUTYH-associated polyposis: Review and update of the French recommendations established in 2012 under the auspices of the National Cancer institute (INCa)

MUTYH-associated polyposis (MAP) was first described in 2002. It is an autosomal recessive condition associated with germline pathogenic variants of both MUTYH alleles. In 2011, a group of French experts reviewed the available data on this syndrome and established recommendations concerning the indications and strategies for molecular analysis of the MUTYH gene in index cases and their relatives, as well as the clinical management of affected individuals under the auspices of the French Institut National du Cancer (INCa). Some of these recommendations have become obsolete as a result of recent progress, especially those concerning the molecular strategy for MUTYH testing, as this gene has recently been included in a consensus panel of 14 colorectal cancer predisposition genes, justifying revision of the previous report. We report here the revised version of this work, which successively considers the phenotype and tumor risks associated with this genotype, differential diagnoses, criteria and strategy for molecular genetic testing and recommendations for the management of affected individuals. We also discuss the phenotype and tumor risks associated with monoallelic pathogenic variants of MUTYH.