Abstract
This multicentre study addresses the genetic spectrum of colorectal polyposis in China. We analyzed 120 patients with over 10 adenomas using a 139-gene next-generation sequencing panel and multiplex ligation-dependent probe amplification. Findings revealed that 89 patients carried pathogenic germline variants, primarily in the APC gene. Notably, one patient had both APC and BRCA2 variants from different parental lines. Our results indicate a higher APC mutation rate compared to prior studies, primarily consisting of nonsense mutations. This research represents the first multicentre clinical investigation in China, highlighting significant differences in mutation profiles compared to the study conducted by the research team from Germany. Since patients were categorized by adenoma count, with none in the 10-19 range diagnosed with hereditary tumors, we recommend delaying genetic testing for those with fewer than 20 adenomas, while emphasizing the need for prompt testing for higher counts.