Genome Instability and Mutation Module

Module genome_instability_mutation 6 disorders Pathograph 4

A conserved mechanism module for the enabling characteristic of cancer (Hanahan & Weinberg): genome instability and mutation. Genome instability is the engine that generates the genetic diversity upon which selection acts during tumor evolution, accelerating acquisition of every hallmark capability. The conserved causal chain runs from an initiating insult that compromises genome integrity - inactivation of a "caretaker" genome-maintenance gene (mismatch repair, homologous recombination/BRCA, nucleotide-excision repair) and/or oncogene-induced DNA replication stress - through failure of DNA-damage surveillance and repair (frequently compounded by loss of the p53 and ATM/ATR checkpoint barriers), to an elevated mutation rate and chromosomal instability (the mutator phenotype). The resulting heritable diversity (point mutations, copy-number changes, aneuploidy, structural rearrangements) fuels clonal evolution and the stepwise acquisition of hallmark traits. Individual disorder entries declare conformance via conforms_to, substituting the tumor-type-specific caretaker lesion (e.g., MMR loss/microsatellite instability in Lynch syndrome, BRCA1/2 loss in HBOC, oncogene-induced replication stress in TP53/ATM-mutant sporadic cancers). The specific HRR/BRCA-deficiency therapeutic vulnerability is detailed in dna_repair_synthetic_lethality.

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Pathophysiology Nodes

4 shared nodes are defined in this module.

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Cell Types

No cell types are annotated for this module.

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Biological Processes

Notes

This is a mechanism module, not a specific disease. Disorder entries reference individual nodes via conforms_to (e.g., "genome_instability_mutation#Mutator Phenotype and Chromosomal Instability"). The module defines the expected pathophysiology structure; conforming nodes in disorder files should include the corresponding biological processes and causal edges, specialized to their tumor context. Key tumor-specific substitutions: Lynch syndrome uses mismatch-repair loss producing microsatellite instability and hypermutation; HBOC uses BRCA1/2-driven HRR deficiency; many sporadic cancers use oncogene-induced replication stress with TP53/ATM loss. The synthetic-lethal therapeutic exploitation of HRR deficiency (PARP inhibitors, platinum) is captured in dna_repair_synthetic_lethality. Key conformance target: "genome_instability_mutation#Mutator Phenotype and Chromosomal Instability".

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Used By Disorder Entries

Esophageal Carcinoma via Chromosomal Instability and Mutator Phenotype → Mutator Phenotype and Chromosomal Instability

Glioblastoma, IDH-Wildtype via Chromosome 7 Gain and Chromosome 10 Loss → Mutator Phenotype and Chromosomal Instability

Hepatocellular Carcinoma via Accumulation of Driver Mutations → Mutator Phenotype and Chromosomal Instability

Lynch Syndrome via DNA Mismatch Repair Deficiency → Genome-Maintenance Defect or Replication Stress , Microsatellite Instability → Mutator Phenotype and Chromosomal Instability

MSI-High Colorectal Cancer via DNA Mismatch Repair Deficiency → Genome-Maintenance Defect or Replication Stress , Microsatellite Instability → Mutator Phenotype and Chromosomal Instability

Small Cell Lung Cancer via Genomic Instability → Mutator Phenotype and Chromosomal Instability

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Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence-backed metadata.

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Pathophysiology

Genome-Maintenance Defect or Replication Stress

trigger

Genome integrity is compromised by either inactivation of a caretaker genome-maintenance pathway (DNA mismatch repair, homologous-recombination repair/BRCA, nucleotide- or base-excision repair) or by oncogene-induced DNA replication stress, in which deregulated proliferative signaling forces aberrant origin firing and replication-fork collapse. Either insult increases the burden of unrepaired DNA lesions.

DNA Repair GO:0006281 DECREASED DNA Replication GO:0006260 ABNORMAL

Used by disorders

Lynch Syndrome as DNA Mismatch Repair Deficiency

MSI-High Colorectal Cancer as DNA Mismatch Repair Deficiency

Downstream

Failure of DNA Damage Surveillance and Repair

Failure of DNA Damage Surveillance and Repair

effector

Accumulating DNA lesions are normally detected by the DNA-damage response (ATM/ATR-CHK signaling) and either repaired or, if irreparable, routed to p53-dependent arrest, senescence, or apoptosis. When repair is deficient and/or the checkpoint barrier is itself disabled (TP53, ATM, or CDKN2A loss), damaged cells continue to divide and propagate their lesions instead of being eliminated.

DNA Integrity Checkpoint Signaling GO:0031570 DECREASED DNA Damage Response GO:0006974 ABNORMAL

Downstream

Mutator Phenotype and Chromosomal Instability

Mutator Phenotype and Chromosomal Instability

central effector

The combination of defective repair and failed surveillance yields an elevated, heritable rate of genomic alteration - the mutator phenotype. Depending on the underlying defect this manifests as a hypermutated / microsatellite-unstable genome (MMR loss), a homologous-recombination-deficiency mutational signature (BRCA loss), or chromosomal instability with aneuploidy and structural rearrangements (replication stress, checkpoint loss). This is the conserved central node that disorder-specific caretaker lesions converge upon.

DNA Repair GO:0006281 DECREASED

Used by disorders

Esophageal Carcinoma as Chromosomal Instability and Mutator Phenotype

Glioblastoma, IDH-Wildtype as Chromosome 7 Gain and Chromosome 10 Loss

Hepatocellular Carcinoma as Accumulation of Driver Mutations

Lynch Syndrome as Microsatellite Instability

MSI-High Colorectal Cancer as Microsatellite Instability

Small Cell Lung Cancer as Genomic Instability

Downstream

Accelerated Clonal Evolution

Accelerated Clonal Evolution

consequence

The heritable genetic diversity generated by the mutator phenotype provides the substrate for Darwinian selection within the tumor. Variant subclones bearing advantageous alterations are selected and expand, accelerating the stepwise acquisition of the other hallmark capabilities (proliferative signaling, growth-suppressor evasion, immortality, invasion) and driving intratumoral heterogeneity, therapy resistance, and progression.