Italian Experts:
Francesca Marcon, Istituto Superiore di Sanità
Eugenia Cordelli, ENEA
Genotoxicity testing for risk assessment has the aim to identify substances causing genetic alterations in somatic and/or germ cells. Genetic alterations in somatic cells may cause cancer and have also been related to degenerative conditions such as accelerated aging, immune dysfunction, cardiovascular and neurodegenerative diseases. In germ cells, DNA damage is associated with spontaneous abortions, infertility or heritable damage to the offspring.
Assessment of the genotoxic potential of a chemical is possible by the use of multiple tests (i.e. a test battery) that can detect gene mutations, chromosome damage and aneuploidy as no individual test can simultaneously provide information on all endpoints. The key aspects of testing substances for their genotoxic potential are described in the individual OECD TGs for the various genotoxic endpoints.
Over the past 20 years, there has been significant technological and scientific progress on mechanisms underlying genotoxicity. To improve regulatory assay performance and data interpretation, OECD began updating TGs in 2010. TG were revised to:
- improve clarity and consistency
- improve statistical power
- refine methodology to improve relevance of results
- provide up-to-date recommendations for acceptability criteria and data interpretation
In April 2014 the OECD Working group of National Coordinators of the Test Guidelines Programme approved revised TGs for in vitro and in vivo micronucleus (TG487, TG474), and chromosomal aberration tests (TG473, TG475), and a new TG for in vivo Comet assay (TG489).
