Putting pancreatic adenocarcinoma (PAAD) screening into perspective for high-risk individuals could significantly reduce cancer morbidity and mortality. Previous studies have profiled somatic mutations in PAAD. In contrast, the prevalence of mutations in PAAD predisposition genes has not been defined, especially in the Asian population. Using a multi-tier cohort design and whole genome/exome sequencing, we create a comprehensive germline mutation map of PAAD in 1,123 Chinese cancer patients in comparison with 11 pan-ethnic studies. For well-known pathogenic/likely pathogenic germline variants, Chinese patients exhibit overlapping but distinct germline mutation patterns comparing with Western cohorts, highlighted by lower mutation rates in known PAAD genes including BRCA1, BRCA2, ATM, CDKN2A, and CHEK2, and distinct mutations in CFTR, RAD51D, FANCA, ERCC2, and GNAS exclusive to Chinese patients. CFTR emerges as a top candidate gene following loss of heterozygosity analysis. Using an integrative multi-omics and functional validation paradigm, we discover that deleterious variants of uncertain significance may compromise CFTR's tumor suppressor function, and demonstrate the clinical relevance by using patient derived organoids for drug screen. Our multifaceted approach not only deepens the knowledge of population differences in PAAD germline mutations but also unveils potential avenues for targeted therapeutic interventions.