A team led by Kathy Niakan, a pioneer in genome editing in embryos in the UK, has confirmed that these techniques are still not ready for clinical use due to major safety concerns that have not yet been resolved.

Genome editing of human embryos

Since the new CRISPR genome editing technique was first applied to human embryos in 2015  (HERE), various lines of research on embryo gene editing have been launched in different countries, with the first study of this type recently authorized in Spain (see HERE). The findings of this research agree that this tool produces unintended side effects on the genome. Accordingly, the international scientific community concurs that it is not yet time to apply this technique in clinical practice to implant modified embryos in women to produce babies (read HERE). In spite of this, we are all aware of what happened in November 2018 in China, where scientist He Jiankui acted against this consensus and the first genetically modified babies were born (see HERE).


“The human being can in no way constitute a model of experimentation.”


Now, an article (read HERE) published on the online server bioRxiv confirms that safety problems persist. The principal researcher of the paper is Kathy Niakan, whose team from the Francis Crick Institute in London was the first to obtain permission in the UK to carry out these types of experiments.

These researchers used the CRISPR tool in human embryos that had been donated for research, with the aim of studying the genetic bases of the early stages of human development (in particular they studied the role of the POU5F1 gene). When they analyzed the edited embryos, they found that many of them contained significant unintended editing outcomes, which could lead to serious consequences in modified individuals.

Further basic research to assess the safety of genome editing of human embryos technique is proposed

Thus, the authors of the aforementioned article concluded that: “[Their] work underscores the importance of further basic research to assess the safety of genome editing of human embryos techniques, which will inform discussions about the potential clinical use of this technology.”

Our statement

We agree that the findings of the research do not support the application of genome editing in embryos in clinical practice. Nonetheless, as we have said in previews articles, we are opposed to the fact that progress in this field is based on experimentation with thousands of human embryos that are then destroyed. The human being can in no way constitute a model of experimentation.