genomic scar signature
Patterns of chromosomal alterations that provide evidence of past DNA repair deficiencies, particularly homologous recombination dysfunction.
Full Definition
A genomic scar signature represents the cumulative chromosomal damage patterns that result from defective DNA repair mechanisms, serving as molecular evidence of historical repair pathway dysfunction even when the original causative mutation may no longer be detectable. These signatures are particularly important in identifying tumors with homologous recombination deficiency, as they can persist even after the loss of BRCA function has been restored through secondary mutations. The signatures include specific patterns of copy number alterations, chromosomal rearrangements, and mutational processes that serve as biomarkers for treatment sensitivity, particularly to PARP inhibitors and platinum-based chemotherapy.
Usage
Usage note: Distinguish from active mutations versus historical evidence of repair dysfunction.
In Context
- "Despite wild-type BRCA status, the genomic scar signature suggested homologous recombination deficiency and potential PARP inhibitor sensitivity." — Molecular tumor board discussion
- "The genomic scar signature analysis revealed high levels of chromosomal rearrangements consistent with DNA repair dysfunction." — Research publication