Research shows problems with proving unintended genetic changes
13 August 2023 / A new US study has reviewed findings on human and animal cells, and shows that CRISPR/Cas gene scissors frequently cause unintended genetic changes. The scientists emphasise that these changes often remain undiscovered with commonly used methods of detection, as these very often only examine either short or just selected gene segments, and are thus insufficient in many cases.
Unintentional genetic changes triggered by gene scissors include the loss of large and small sections of the genetic material (deletions) and also long or short additionally inserted DNA sequences (insertions). Among other things, also the loss or reorganisation of larger sections of chromosomes was observed.
According to the authors, in many cases it is not sufficient to use only one method to detect damage in the genome. It actually can require a combination of several methods. They are warning that the use of gene scissors - e. g. in the context of gene therapy – may constitute a major risk to health if unintended changes in the genome are overlooked.
While unintended genetic changes caused by new genetic engineering (New GE or new genomic techniques, NGT) are the subject of numerous scientific publications in the field of human medicine, they have so far received little attention in the field of plant breeding. This could be one reason why the EU Commission generally assumes that unintentional genetic changes in NGT plants are not associated with any particular risk. These unintended genetic alterations are largely excluded from risk assessment in a proposal for the future EU regulation of new genetic engineering.
In fact, different risks must be assumed for plants than for clinical applications in humans. However, also in the case of NGT plants, no statements can be made about safety without a detailed examination. Changes in the genetic material of plants can have a wide range of adverse effects on the environment, including on insects, soil organisms and the food web. The particular consequences depend on the function of the genes affected by the intended or unintended changes.
Mutations also frequently occur spontaneously in many genomic regions of plants which have a high degree of flexibility within their genome to deal with these mutations. However, gene scissors can alter gene functions that are otherwise well protected by the cells. As a result, NGT plants are often very different to conventionally-bred plants. From a scientific point of view, it cannot, therefore, be denied that plants whose genetic material has been modified by NGTs must first be thoroughly examined before safety can be assumed. Mandatory risk assessment of these plants will thus continue to be necessary in the future.
Christoph Then, firstname.lastname@example.org, Tel + 49 151 54638040