POLE encodes the catalytic subunit of DNA polymerase epsilon, the enzyme that replicates the leading strand of DNA during cell division and participates in DNA repair. It contains a proofreading domain that corrects replication errors, keeping the accumulation of mutations in check. Germline mutations in POLE cause polyposis and predispose to colorectal cancer, and are also linked to a rare syndrome of facial dysmorphism, immunodeficiency, livedo, and short stature. Somatic mutations, particularly in the proofreading domain, occur in colorectal and endometrial cancers, where they drive an ultra-mutated tumor phenotype and are associated with better responses to immune checkpoint inhibitors.

POLE germline variants predispose to polyposis and colorectal cancer, mostly through missense changes in the proofreading (exonuclease) domain. This variant is a synonymous change (p.Ser988=) in exon 25, outside that domain, with no predicted splice impact. Its VUS classification reflects that it does not match the gene's established disease mechanism, while population-frequency and functional evidence needed for a benign call are lacking.