Case Report: Expansion of the POLD1-related polymerase proofreading-associated polyposis spectrum: first report of duodenal adenocarcinomas and characterization of two likely pathogenic variants

Our report expands both the phenotypic and molecular spectrum of <i>POLD1</i>-associated PPAP by documenting the first duodenal adenocarcinomas in germline carriers and describing a novel variant. These findings emphasize the need for systematic upper gastrointestinal surveillance, support the systematic reporting of rare <i>POLD1</i> variants to refine genotype-phenotype correlations, and underline the potential therapeutic relevance of identifying carriers in the context of immunotherapy.