Gene-editing summit

Gene-editing technology vaulted into the public consciousness with Science magazine naming the CRISPR–Cas gene-editing tool its 2015 Breakthrough of the Year.

CRISPR–Cas is a programmable nuclease-enzyme system that allows scientists to edit specific sequences of DNA, potentially resulting in profound changes to an organism. Importantly, the CRISPR–Cas technology is specific, accurate and easily incorporated into laboratory methods.

But the potential uses of gene-editing technologies — from fixing genetic abnormalities to genetic customization of offspring — have raised scientific, ethical and societal questions. Now that we can edit the human genome, should we?

This question and others arose during the International Summit on Human Gene Editing in December in Washington, D.C. Hosted by the U.S. National Academy of Sciences to discuss the current state of gene-editing science and to consider scientific and ethical implications associated with human gene editing, the summit attracted, among others, scientists from the Chinese Academy of Sciences, the United Kingdom's Royal Society and the U.S. National Academy of Medicine.

In a public statement released after the three-day summit, the event’s organizers addressed human gene editing in three separate categories: basic research, somatic clinical use and germline clinical use.

They called for exhaustive basic research on gene editing in human cells to determine potential benefits and risks of clinical use. They said that such research will enhance our fundamental scientific understanding of the biology of human embryos and germline cells.

Since somatic cell gene editing affects only the cells of the body and not reproductive germ cells, this type of gene editing could be used in patients without the risk of transmitting genetic modifications to future generations. The summit organizers said that somatic cell gene editing has the potential to be used safely and effectively in clinical applications when carefully governed by existing regulatory frameworks.

With regard to germ cell gene editing, the organizers called for caution, writing, “It would be irresponsible to proceed with any clinical use of germline editing unless and until (i) the relevant safety and efficacy issues have been resolved, based on appropriate understanding and balancing of risks, potential benefits and alternatives and (ii) there is broad societal consensus about the appropriateness of the proposed application.” The committee stopped short of issuing a ban on germline gene editing but reiterated that human gene-edited cells should not be used to establish a pregnancy until extensive basic research is done.

The committee also called for an ongoing discussion of human gene editing so that more nations and diverse stakeholders can participate in the conversation.

The NAS has undertaken a comprehensive study of human gene editing led by R. Alta Charo of the University of Wisconsin–Madison and Richard Hynes of the Massachusetts Institute of Technology. The final report, due later this year, will cover the science behind gene-editing technology; potential biomedical uses in research and medicine; and associated ethical, legal and social considerations.

The American Society for Biochemistry and Molecular Biology supports the summit organizers’ call for exhaustive basic research on the effects of gene-editing human cells to guide how this technique should be used for clinical applications.

Sarah Martin Sarah Martin is the science policy fellow at the ASBMB.