A scientist in Sweden has become the first to edit genes in healthy human embryos.
Dr Fredrik Lanner, a developmental biologist at the Karolinska Institutet in Stockholm, is using the revolutionary genome-editing technique CRISPR/Cas9 in human embryos in order to learn more about early embryogenesis.
CRISPR/Cas9 can be used to remove or replace target genes much more accurately and efficiently than previous genome-editing technologies. Dr Lanner is knocking out genes in order to reveal their function. He states that in the future this knowledge may aid research into possible treatments for infertility and diseases such as Parkinson's.
'[CRISPR/Cas9] actually opens the door to start to look at this for the first time, because we could not do this at all previously in the human embryo. The technology was just not efficient enough to try to look at individual gene function as the embryo develops,' Dr Lanner stated in an interview with NPR.
Dr Lanner has edited at least a dozen embryos, but is still studying his results and refining his techniques. The embryos that undergo genome editing in Dr Lanner's work will not be implanted and will be destroyed after two weeks. This requirement also applies to research involving genome editing in human embryos in the UK; edited embryos must be destroyed 14 days post-fertilisation.
Despite this time constraint, some people are worried that this work is an ethical 'slippery slope'. It is feared that detrimental changes to the human genome may cause novel diseases to arise in future generations. Another concern is a future in which prospective parents may be able to design the characteristics of their children.
Dr Lanner recognises these concerns, saying: 'It's not the technology that should be taken lightly. So I really of course stand against any sort of thought that one should use this to design designer babies or enhance [for] aesthetic purposes and so on.'
Dr Lanner believes that research projects like his should continue in the face of these ethical concerns because of the potential benefits: treatments for disease and infertility.
Last year the National Academy of Sciences, Engineering and Medicine established a Human Gene-Editing Initiative in response to advances in the field of genome editing. The group has suggested that while fundamental research like Dr Lanner's is acceptable, applying CRISPR/Cas9 in human reproduction requires much more ethical and scientific attention.
UK scientists have also gained approval to perform similar genome-editing research later this year (see BioNews 837), while last year a team of Chinese scientists carried out genome editing in non-viable human embryos (see BioNews 799).
On Wednesday 7 December, the Progress Educational Trust is holding a one-day conference entitled 'Rethinking the Ethics of Embryo Research: Genome Editing, 14 Days and Beyond', where speakers will include the first researcher licensed by the UK regulator to use genome editing in human embryo research.