Not that long ago I wrote about the use of CRISPR-CAS9 systems and the ongoing ethical debate on their use in humans. As it turns out this future is even closer that I might initially have thought. This week a Chinese group published a paper where they used these systems to do genome editing in non-viable human embryos.
The original paper is available here: http://link.springer.com/article/10.1007%2Fs13238-015-0153-5 And nature news piece on the topic can be found her: http://www.nature.com/news/chinese-scientists-genetically-modify-human-embryos-1.17378 Finally the findings were also covered in Swedish mainstream press (in Swedish) here: http://www.dn.se/ekonomi/forsta-manskliga-genmanipulationen-genomford/
The study itself draws attention to some problems related to genome editing using these techniques. The poor success rates (28 out of 86 embryos tested were successfully spliced) and problems with off-target mutations hinder the immediate clinical use of the technique. These are however problems that I’m sure will be addressed by technology development.
More importantly I think that this highlights the importance of establishing ethical frameworks for the use of gene-editing. Interestingly the paper was rejected both by Nature and Science “in part because of ethical objections” – it remains to be seen if such objections will hold in the future.
Personally I’m as of yet undecided on the morality of carrying out gene editing in embryos. While the promise of cures to heritable disease is wonderful, it’s easy to see a slippery slope from there into more dubious uses. Also it warrants the questions of what is to be considered a disease/disability.
Today at the SciLifeLab Large Scale Human Genome Sequencing Symposium Dr. Anna Lindstrand spoke about a study indicating CTNND2 as a candidate gene for reading problems. Are such mild disabilities to be considered for gene editing? Maybe not – but where do we draw the line? Once the technology is available I have little doubts that some will want to use it produce “genetically enhanced” humans.
The Nature news article referenced above ends of with the somewhat ominous quote: “A Chinese source familiar with developments in the field said that at least four groups in China are pursuing gene editing in human embryos.” Certainly we are going to hear more on this topic in the future.