On-target effects of genome editing techniques

On-target effects of genome editing techniques

Introduction
Genome editing encompasses new forms of genetic engineering techniques being increasingly applied to the development of agricultural and biomedical technologies, by ‘editing’ the DNA of living organisms (i.e. their ‘genome’), including plants, animals and human cells. The genome editing process involves the use of biological molecules (enzymes) which cut the DNA and various mechanisms which then repair it. Arguments over the safety and efficacy of genome editing techniques at the molecular level often hinge on aspects of their ‘precision’ in targeting DNA sequences of interest, and the ‘indistinguishability’ of engineered traits from mutations that may arise naturally.
Claims of genome editing precision or specificity have been repeatedly challenged by the accumulation of studies showing unintended effects, such as ‘off-target’ modification of additional regions of the genome to the ‘target site’ chosen by the developers. Evidence to date also reveals the issue of unintended ‘on-target’ effects that include various forms of genetic damage that scar edited genomes. This genetic damage is a common side-effect of the process of genome editing, resulting from error-prone mechanisms of DNA repair following genome editing induced DNA breaks, and the deployment of additional, less understood DNA repair pathways by the cell. However, unintended effects at the target site have received much less attention, and efforts to characterise and detect them are not routinely performed. Not only do such effects fundamentally challenge the notion of indistinguishability and safety, but they raise important questions regarding whether such side-effects are contributing to a bottleneck of gene edited crops reaching commercialisation.
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Read on here: https://gmwatch.org/en/news/latest-news/19901
The original GeneWatch UK report is available for download here:
http://www.genewatch.org/uploads/f03c6d66a9b354535738483c1c3d49e4/genome-editing-techniques-fin.pdf
It is reproduced on GMWatch with the permission of GeneWatch UK.

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