Genome Editing Human Embryos

It seems that the ethical buzz was coming from a paper by a unknown Chinese group not involved with any of the genome editing pioneers. They took the unviable leftovers from In Vitro Fertilization (IVF) and then genome edited these human ’embyros’.

Interestingly, the success was quite poor. There was:

  • A Low Editing Rate
  • Toxicity
  • Rampant Off-Target effects

This in stark contrast to the use of CRISPR/Cas9 in dozens of animals ranging the entire tree of life. Ultimately, it doesn’t appear to be human limitation, as mammals including monkeys have been done much more successfully, but rather a result of poor experimental design, as these effects can be almost entirely attenuated by good guide RNA design and it seems that they didn’t considers the different chromatin states of embroynic stem cells that would influence off-target effects.

This was probably due to rushing the design in order to claim to be the first to alter human embryos, as opposed to the much more informative, well done, and ethically appeasing altering of Human Embryonic Stem Cells (HESCs) that showed off human CRISPR/Cas9 genome editing can be done properly in germ-line cells, with all its perks, and lead to breakthrough at the basic level in addition to all the clinical potential of genome editing technologies.

This speculation is apparent as there was a large outcry when the Chinese authors tried the ‘high impact’ journals and it seems they settled on a much lesser known open access that has additional concerns with the peer review process, mainly that it took one day, instead of 6 months to a year of the purgatory that is usually is.

Ultimately, it seems this was rushed for fame of unknown researchers and unknown journal, rather than science. But it’s still a Pubmed indexed journal with an impact factor and published by Springer. It is a bit of a shame as the Pandora’s box of CRISPR in human embryos needed to be opened quite slowly and carefully. The parts are all relatively easily accessible and not restricted, which is what has lead to spectacular pace of CRISPR/Cas9 genome editing development. While the field has its leaders developing CRISPR for the clinic the proper way, the technology it is now at the place where it can be picked up by many more who may not just be interested in the somatic line. But here we are now, waiting to see if genome editing technology will change the world, by curing inherited human disease or being used to design sci-fi nightmares. Either way, human inheritance has entered the designer era.

Sources:

  1. The Primary Publication
  2. Nature News
  3. Stem Cell Assays