Stem Cells in Focus

The Genetic Modification of Humans has (Probably) Occurred – What Now?

  • 6 May, 2019

Chinese scientist He Jiankui shocked the world in November 2018 when he reported the birth of twin girls born from genetically altered embryos, with another genetically-altered baby on the way. Although this report of genetic modification has not been, and may never be, independently confirmed due to privacy concerns, the birth of the so-called “CRISPR babies,” named for the DNA-editing approach used to alter their genome during the IVF process, has had a seismic impact  throughout the scientific community and beyond.

Jiankui’s news was met with immediate criticism all corners of the globe. If true, he performed a reckless experiment on humans that violated the international scientific and medical consensus, lacked the proper ethical and regulatory review, and could potentially have significant health consequences for the girls as well as broader consequences for society. Numerous scientific organizations, including the ISSCR, have released statements condemning the clinical application of editing the DNA of human embryos.

Scientific and Ethical Concerns

Ironically, the unexpected announcement occurred during an international summit on human gene editing, designed to convene experts from a variety of disciplines to debate and discuss the “many questions [that] remain about the science, application, ethics, and governance of human genome editing.” Since the discovery of CRISPR, the scientific community has recognized the broad medical applications of this approach to correct genetic defects as well as the ethical and societal implications, particularly if and/or when it would be used to correct genetic defects in the embryo. Genetic changes to the embryo have the potential to be incorporated into all cells, including those that give rise to sperm and eggs (also known as germline cells), and thus the changes could be passed onto future generations. This is not true for genetic changes to adult cells outside of the gonads.

A host of ethical and societal implications arise when considering the potential to inherit man-made changes to the human embryonic genome. Some are detailed in the recent report from the Nuffield Group, such as:

  • under what circumstances would it be acceptable to edit the human embryonic genome?
  • what are the human welfare implications of such modifications?
  • what level of safety and scientific evidence is required before its feasible to go forward with this approach?

While the report concludes that there are “circumstances in which human genome editing interventions should be permitted,” it also states that they should not be done until there is an “inclusive societal debate” on the issue(s).

In addition to the ongoing, and now intensified, discussions taking place, there are a number of groups working on new initiatives to establish a more rigorous framework and guidelines for this research and its potential clinical application.

  • The World Health Organization has convened an Expert Advisory Committee to “develop global standards for governance and oversight of human genome editing.” Among the topics they are discussing is a central registry on human genome editing “in order to create an open and transparent database of ongoing work.”
  • Independently, an international collaboration of scientific academies, the U.S. National Academy of Sciences (NAS),the U.S. National Academy of Medicine (NAM), and the UK Royal Society are leading an international commission to discuss the scientific and regulatory issues around editing human embryos.
  • An international group of scientists have also issued an international governance framework and along with another group called for a moratorium on any clinical embryonic genome manipulation “until serious scientific, societal, and ethical concerns are fully addressed.”
  • Individual countries are proposing tightening regulations around gene editing research.

Important Potential for Medicine

Gene editing, whether in adult cells or the early embryo, has the potential to change how we treat and think about disease. With the change of a single nucleotide, in some cases, a potentially lethal disease might be cured. Before that happens, however, important scientific and ethical issues must be considered and worked through. He Jiankui’s announcement in late 2018 has catapulted these conversations forward, and researchers, clinicians, ethicists, and others are now actively engaged in discussions about whether and how human germline genome editing can responsibly become part of medical treatment. Through the various international working groups, scientific societies like the ISSCR, and individual countries, these issues will be addressed in months to come, with the rest of the world waiting and watching.