CHINA – A research team from China has used the genetic engineering techniques to modify human embryos.  It is the second time this has been done – first time also by researchers from the same country.

In the study, modification was made on non-viable embryos and on a gene linked to the beta thalassemia.  The research group from Guangzhou Medical University announced they used the editing technique of genomic CRISPR to change human embryos (always non-viable) in an attempt to induce changes in resistance to infection with HIV.

 They used embryos produced by assisted fertilization techniques but non-viable (ie are able to perform only the first divisions) because of an extra set of chromosomes.

The idea of the researchers was to use the CRISPR – genomic editing method extremely precise and relatively easy – to change CCR5 gene involved in infection with HIV.  Mutations in this gene have been observed in some people naturally resistant to HIV, as an altered function of the corresponding protein prevents the virus to enter and infect cells.

Out of 26 embryos the researchers modified only 4, according to Nature News, but not all embryos had the genetic modification desired in the CCR5 gene.  The embryos were then destroyed three days later.

The technical success of the experiment has been rather limited, and some experts believe it is only providing  further proof that CRISPR works on human embryos, which is already  an undisputed belief, but that there are still many technical difficulties to overcome in achieving precision editing.

As the authors emphasized that their work is just solely proof-of-concept.  They believe that any effort to produce genetically modified humans through the alteration of early embryos needs to be strictly prohibited until both ethical and scientific issues can be resolved.

Only a couple of months ago the United Kingdom faced some backlash  for allowing use CRISPR to modify human embryos for research purposes with the ultimate goal of finding new treatments against infertility. The ethics of modifying embryos has divided scientists.

This study was published on April 6 in the Journal of Assisted Reproduction and Genetics.