Identification of Genetic Factors Related With Nonhereditary Colorectal Polyposis and Its Recurrence Through Genome-Wide Association Study

Background: Many patients with colorectal polyposis demonstrate negative results in germline mutation test. This study aimed to uncover genetic variants associated with nonhereditary colorectal polyposis using a genome-wide association study (GWAS).

Methods: At a single referral university hospital, between January 2012 and September 2021, 638 patients with ≥ 10 biopsy-proven cumulative polyps on colonoscopy without germline mutations related to hereditary colorectal cancer or polyposis were included. The control group comprised 1863 individuals from the Korea Medical Institute, each having undergone at least two colonoscopies, all of which were normal. This study utilized GWAS to identify susceptibility loci for nonhereditary colorectal polyposis. Genetic differences between patients with and without ≥ 10 polyp recurrences were analyzed using Cox proportional hazards models.

Results: GWAS revealed 71 novel risk single-nucleotide polymorphisms (SNPs) not seen in previous colorectal cancer and polyp GWAS. Five genes (UPF3A, BICRA, CBWD6, PDE4DIP, and ABCC4) overlapping seven SNPs (rs566295755, rs2770288, rs1012003, rs201270202, rs71264659, rs1699813, and rs149368557), previously linked to colorectal cancer, were identified as significant risk factors for nonhereditary colorectal polyposis. Two novel genes (CNTN4 and CNTNAP3B), not previously associated with colorectal diseases, were identified. Three SNPs (rs149368557, rs12438834, and rs9707935) were significantly associated with higher risk of recurrence of polyposis. The gene overlapping with rs149368557 was ABCC4, which was also significantly associated with an increased risk of nonhereditary colorectal polyposis.

Conclusion: This study identified 71 novel risk variants for nonhereditary colorectal polyposis, with three SNPs (rs149368557, rs12438834, and rs9707935) indicating significant associations with increased risk of polyposis recurrence.