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's established disease-driving missense variants cluster in the exonuclease-domain hotspot region (residues 286-459), while Arg762Trp lies in the polymerase domain, outside it. Its ultra-low population frequency (0.0008% or less, zero homozygotes) is consistent with a rare disease-associated allele, but the absence of functional, segregation, or recurrence evidence leaves it a VUS rather than a pathogenic or benign call.