Russian scientist aims to restart controversial CRISPR babies study

12 Jun 2019

A mouse embryo in a jar. Image: © Jan/

Scientists have expressed concern after a Russian scientist said he plans to follow controversial research into CRISPR-edited babies.

Months after Chinese scientist He Jiankui received worldwide condemnation for going rogue and editing the genomes of babies using the gene-editing tool CRISPR, a Russian scientist has announced he plans to follow on this research.

At the time, He said the children’s genomes had been edited to make them resistant to HIV. However, since then, it’s been revealed that the scientist’s actions could have seriously impacted the cognitive abilities of the twins.

Speaking with Nature, Denis Rebrikov of the Pirogov Russian National Research Medical University in Moscow said that while he plans to repeat the controversial experiment, it will be more successful than the Chinese experiment and he could receive state and regulatory approval to do so.

The experiment will target the same gene as the Chinese experiment – CCR5 – but Rebrikov claims that his CRISPR technique will bring greater benefits, and be safer and more ethically justifiable. The molecular biologist said he plans to disable the gene – which encodes a protein that allows HIV to enter cells – in the embryos that will be implanted in HIV-positive mothers.

By comparison, He’s study modified the gene in embryos of the father with HIV, which is deemed to have little benefit because of the minimal risk of him passing it on to his child.

Rebrikov claimed that he has already made an agreement with a treatment centre to recruit HIV-positive women who want to take part in this latest CRISPR experiment. However, while Russia has a law that bans genetic engineering in most instances, there is no clear rule against gene-editing an embryo.

‘Crazy enough to do it’

The scientist expects the country’s health ministry to state the legality of the procedure in the next nine months, with plans to implant the CRISPR-edited embryos by the end of this year if he receives approval.

Before he begins, Rebrikov hopes by doing this and approaching two other government agencies, he will get the legal backing that He did not. Only then does he think he would be “crazy enough to do it”, saying he feels compelled to help women with HIV.

Despite his efforts to seek approval, Rebrikov’s plan has received widespread condemnation from the scientific community, including CRISPR-Cas9 pioneer Jennifer Doudna, who said this was “not surprising, but it is very disappointing and unsettling”.

There are also fears over what would happen if CCR5 is disabled; while a lot is known of its role in HIV entry, not much is known about what side effects could come with it. For example, one recent study suggested that those without a working CCR5 gene may have a shortened lifespan.

In response to these fears and gene-editing tools such as CRISPR in general, Rebrikov claimed that his technique will have no ‘off-target’ mutations. He plans to publish his preliminary findings in an upcoming journal issue.

Colm Gorey was a senior journalist with Silicon Republic