| Popis: |
Mutational processes in germline and in somatic cells are vastly different, and it remains unclear how the same genetic background affects somatic and transmissible mutations. Here, we estimate the impact of an inherited pathogenic variant in the exonuclease domain of polymerase delta (Polδ) on somatic and germline mutational processes and cancer development. In germline cells and in non-cancer somatic cells, thePOLD1L474P variant increases the mutation burden only slightly, contributing ∼11.8% and ∼14.7% of mutations respectively, although it strongly distorts the mutational spectra. By contrast, tumors developed by carriers of inherited pathogenic variants inPOLD1harbor a DNA rearrangement that results in a homozygous state of the pathogenic variant, leading to an extremely high mutation rate. Thus, mutations in both alleles ofPOLD1gene are required for strong increase in mutation rate suggesting recessiveness of Poldδ proofreading. These results show a similar role of Polδ in germline and somatic replication, and, together with previous findings, illustrate the important differences between Polδ and Polε in the disruption of their replication fidelity. |
