July 6, 2020

The Niche

Knoepfler lab stem cell blog

Is ‘genetically modified human’ a loaded name?

Craig MelloShould we be using the term ‘genetically modified human’ in discussions of heritable use of CRISPR in people?

During the still ongoing discussions of genetic modification in the human germline and potentially in actual human beings in the future, an interesting, but difficult question has emerged:

What words or names would be most appropriate for the community to use to refer to potential future human beings that have gene edits?

I have up until now referred to such hypothetical people as “genetically modified humans” or “GM humans” for short.

To me this terminology seems most accurate.

Keep in mind that people bearing gene edits don’t exist and in principle may never come into being, although I think the odds are increasing that this might happen.

It is also worth noting that nearly everyone who has weighed in on the potential production of humans with germline gene edits has been opposed to it.

Others have used the “genetically modified human” terminology as well. For example, Nobel Laureate Craig Mello uses the term “genetically modified humans” (at the ~36 minute time point in video above, HT to Antonio Regalado @antonioregalado, screen shot at top of post from video).

Still, however, I can see how the phrase “GM human”, even if used in a discussion of only hypothetical future beings, could be complicated.  For example, Julian Hitchcock raised the concern on Twitter that the nomenclature “GM Humans” could have negative connotations.

Why is this issue of what to call modified humans important if we are only talking about a hypothetical case scenario that might never become reality?

Even if we are just talking about potential future people who might have gene edits, we need words right now to accurately refer to them during discussions of human germ line gene editing/genetic modification. Such discussions are urgently needed at this time given evolving biotechnology and part of the agenda for dialogue needs to include what happens if (again for lack of a better term currently) GM people are produced.

If GM people were ever created, they would from a scientific perspective indisputably possess genetic modifications from the original genome that they would have inherited or did inherit as a 1-cell embryo. In addition, they would be genetically modified organisms or GMOs. Should we do a PC tap dance around that fact by avoiding the phrase “genetically modified”?

Yet it can be very complicated.

As Hitchcock asked, if a 1-cell embryo has a disease-causing mutation and CRISPR were used to revert that back to a wildtype, healthy genetic state, should we still call that a “genetic modification”?

At the moment I would say “yes”, but I realize this is a difficult issue on a new technology that we are talking about using in a hypothetical application so it’s not a hard-and-fast “yes”.

This kind of question is made even more complex by the fact that CRISPR is not necessarily going to be entirely specific when used somewhat on the fly during human embryogenesis (again hypothetically) so even with correction of a mutation, how can we be 100% sure other unintended genetic modifications didn’t occur?

We also do not know, as Baltimore, et al. pointed out, whether “correction” of a mutation even if done in a perfectly specific hypothetical context, could lead to unintended consequences in a particular specific embryo or the human produced from it. Everything is context dependent.

What if the same kind of technology were used to experimentally try to reduce risk rather than outright try to prevent disease?

What if this approach were used to attempt to alter behaviors or traits?

Can we draw clear lines between these different applications of the same kind of technology?

For the purposes of community discussion today, what might be the best words to use to refer to these hypothetical cases of new versions of humans?

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