August 31, 2017
Is it possible that CRISPR gene editing actually didn’t happen in many of the human embryos in that big Naturepaper that made such news a couple weeks back?
Some doubts have emerged that call the main conclusions of the paper into question and argue that more definitive studies are needed to be sure.
An international team of top scientists led by first author Dieter Egli has responded via a preprint on Biorxiv to that Mitalipov team high-profile Nature paper on CRISPR gene editing of human embryos. Egli, et al. raise the possibility that the CRISPR gene editing as reported in the Nature study may actually not have happened, at least not in every case and perhaps not the way the Ma, et al. paper argued it did (via homology directed repair (HDR)-based CRISPR-Cas9 action specifically depending on interaction between normal maternal and mutant paternal chromosomes).
On one level it isn’t so unusual to see a scientific critique of and technical questions raised about a published paper that made splashy news. However, I see this particular case as a striking turn of events because although the new Egli, et al. piece is very collegial and diplomatic, they convincingly lay out a number of rather compelling reasons why the main conclusions of the Ma paper might be incorrect and the reasons why there may not have been CRISPR gene editing in many of the embryos. To be clear, Egli and colleagues don’t seem to be saying the Ma, et al. paper is definitely wrong, but they describe some quite reasonable ways in which the Ma paper could hypothetically have inadvertently reached incorrect central conclusions.