Mutagenicitate

Mutagenicitate, or mutagenicity, is the property of an agent to induce heritable genetic changes. A mutagen is any substance or factor capable of causing DNA sequence alterations or chromosomal structural changes that can be passed to offspring or propagated in subsequent cell divisions. Mutagenic activity is usually assessed in genetic toxicology and is a key concern in toxicology, pharmacology, and environmental health.

Mechanisms of mutagenesis vary by agent. Chemical mutagens can form DNA adducts, cause alkylation, or intercalate into DNA to disrupt replication, leading to base substitutions or frameshifts. Radiation, including ultraviolet and ionizing radiation, can cause base damage, cross-links, and double-strand breaks, producing a range of mutations and chromosomal aberrations. Biological agents such as transposons and certain viruses can alter genetic material as well. Mutations may be neutral, deleterious, or, rarely, advantageous for an organism; in somatic cells they can contribute to cancer, while germline mutations are heritable.

Testing for mutagenicity commonly uses the Ames test with bacteria to detect mutagen-induced reversions, supplemented by in vitro mammalian cell mutation assays and in vivo micronucleus or comet assays. Regulatory frameworks (for example OECD guidelines) require genetic toxicology data to assess hazard, alongside other toxicological endpoints. It is important to note that mutagenicity is a component of genotoxic risk but does not always correlate directly with carcinogenicity; some mutagens are not carcinogens, and some carcinogens are not detected as mutagenic in certain tests.

Examples of known mutagens include aflatoxin B1, certain nitrosamines, benzene derivatives, and forms of ultraviolet and ionizing radiation.