Genomstabilität

Genomstabilitet (genome stability) is the property of a cell to preserve the structure and sequence of its genome during replication and in response to damage. High genome stability minimizes the accumulation of mutations, chromosomal rearrangements, and copy number changes that can disrupt gene function and genome organization.

Biological foundations: The maintenance of genome stability relies on accurate DNA replication and robust DNA repair. Key pathways include base excision repair, nucleotide excision repair, mismatch repair, homologous recombination, and non-homologous end joining. Surveillance mechanisms such as cell cycle checkpoints detect damage and coordinate repair or apoptosis. Chromatin organization and telomere maintenance also contribute to stability, as do replication fork protection and meiotic recombination controls.

Factors affecting stability: Endogenous sources (replication stress, reactive oxygen species, metabolic byproducts) and environmental factors (ionizing and non-ionizing radiation, chemicals) can induce lesions. Genetic defects in repair genes (for example, BRCA1/2, MMR genes) compromise stability and increase mutation rates. Aging is associated with gradual loss of genome maintenance efficiency.

Consequences and clinical relevance: Genomic instability is a hallmark of many cancers and is linked to tumor heterogeneity and progression. It also contributes to age-related decline and some neurodegenerative diseases. Understanding genome stability informs cancer risk assessment and therapeutic strategies, including targeted repair pathway inhibitors.

Measurement and research: Researchers assess genome stability using karyotyping, array comparative genomic hybridization, whole-genome sequencing, comet assays, γ-H2AX foci, micronucleus tests, and other biomarkers of DNA damage and repair activity.