An unconfirmed report from a news agency, not from a peer-reviewed journal, claims that twin girls have been born following gene modification with the CRISPR-Cas9 technology.
Scientists in China, according to an unconfirmed report from the Associated Press news agency
, have claimed the world's first birth following the genetic modification of embryos. The gene editing, apparently performed by investigator He Jiankui of the Southern University of Science and Technology in Shenzhen, China, was said to have used the CRISPR-Cas9 technology not to cure or prevent an inherited disease but to introduce genetic resistance to HIV infection in the offspring.
If confirmed, the births would be the world's first genetically edited babies. Last year Shoukhrat Mitalipov of Oregon Health and Science University in the USA claimed to have successfully edited the DNA of a large number of human embryos with the CRISPR-Cas9 gene-editing technique, but his report in Nature made clear that the fertilised eggs were never intended for transfer or pregnancy.
This latest report - if verified - takes that work several stages further and into a hugely controversial scientific scenario which is outlawed in most countries. In a YouTube video, also highlighted in the AP report, He Jiankui claims to have eliminated a gene called CCR5 in order to make the babies (twin girls) resistant to HIV should they ever come into contact with the virus.
Most experts commenting so far on the report have condemned the work, noting that these genomic modifications will now remain in the germline. Fertility treatment pioneer Lord Robert Winston told the BBC that, 'if this is a false report, it is scientific misconduct and deeply irresponsible. If true, it is still scientific misconduct'. Others described such experimentation in humans as morally unacceptable. Subsequent reports from China have suggested that He has been suspended by his university.
The AP story came just days before the second International Summit on Human Genome Editing opened in Hong Kong. The widely publicised report on germline editing following the first summit in Washington - organised by US National Academics of Science, Engineering, and Medicine - gave cautious support to the CRISPR-Cas9 technique, but insisted any advance should be subject to strict oversight and only in an ethically approved research setting. As a prelude to this second summit, the organisers now reaffirm that 'many questions remain unanswered concerning the science, application, ethics, and governance of human genome editing'. Of particular concern, they add, is the possibility of genome editing that might lead to heritable alterations 'and applications for purposes other than to treat diseases or disabilities'.
According to the MIT Technology Review, He and colleagues have been recruiting couples in a bid to eliminate the CCR5 gene and thereby render the offspring resistant to HIV, smallpox, and cholera. Data cited in the MIT review as part of the trial listing show that genetic tests had been carried out on fetuses as late as 24 weeks, but at the time of the report nothing was known of their fate - and only after this report did the AP announce the twin births.
Commenting on the claims, Rita Vassena, a former co-ordinator of ESHRE's SIG Stem Cells, said that 'while research on editing the genome of human embryos should continue, clinical applications of this powerful technology are not justified at this moment and should not be conducted before further thorough data on safety and efficacy are obtained' and not before a consensus has been reached among all stakeholders'.