Scientist plans to make more genome-edited babies

A Russian scientist has announced his intention to produce genome-edited babies.

If geneticist Dr Denis Rebrikov were to go through with this proposal, he would become only the second scientist to do this. Dr Rebrikov, who is head of a genome-editing laboratory at the Kulakoc National Medical Research Centre of Obstetrics, Gynaecology and Perinatology in Moscow, told his plans to Nature News.

His announcement comes in the wake of the controversial claim by Chinese scientist Dr He Jiankui last November that he had produced the world's first babies from genome-edited embryos. 

Dr He's claim was met with international outcry (see BioNews 977). Subsequently, there has been heated debate among the scientific community, leading to recommendations that experiments involving edits to the human germline should be banned until an appropriate ethical and safety framework can be implemented. 

Like Dr He, Dr Rebrikov intends to use the CRISPR/Cas9 genome-editing approach to target a gene called CCR5 that encodes a protein used by HIV-1 to enter cells. A specific mutation in this gene, which is found naturally in some individuals, can result in resistance to HIV-1 infection. 

While Dr He chose to delete the CCR5 gene in embryos created from fathers with HIV, Dr Rebrikov instead plans to disable the CCR5 gene in embryos that will then be implanted into HIV-positive mothers.

He claims that this will reduce the risk of the virus being passed on to the fetus. However, some evidence suggests that having an inactive CCR5 gene could cause a range of health risks and shorten an individual's lifespan (see BioNews 1001).

In addition, a major concern of genome-editing technologies is the possibility of off-target effects – misplaced changes to the genome that could have side effects that are not easy to predict. If genome-edited embryos are allowed to grow into babies, then these off-target effects pose a health concern, and can also be passed on to future generations

'The technology is not ready,' CRISPR pioneer Professor Jennifer Doudna, at the University of California, Berkeley, told Nature News. 'It is not surprising, but it is very disappointing and unsettling.'

Dr Rebrikov anticipates that regulations regarding genome-editing in embryos will be clarified by Russia's health ministry in the next nine months. However, he already has an agreement in place with a Russian HIV clinic to recruit participants to his experiment, and is looking to seek approval from three government agencies.

The scientific committee advising the World Health Organisation is unlikely to issue its final recommendations regarding human genome-editing until 2020. However, with experiments like this in the pipeline, many researchers agree that testing and implementing appropriate safety measures should be a priority.