Chris Gyngell and Julian Savulescu, Practical Ethics, April 23, 2015
Human genetic modification has officially progressed from science fiction to science. In a world first, scientists have used the gene editing technique CRISPR to modify human embryos. While the study itself marks an important milestone, the reason it is truly extraordinary is the scientific community’s reaction to it. In refusing to publish this study on ethical grounds, the world’s two leading science journals Nature and Science, appear to be demonstrating a lack of clear and consistent thinking on ethical issues.
The study, eventually published in the journal Protein & Cell, is more a small step than a great leap. CRISPR has been used to modify embryos is a number of other species including primates. It has also been used in human somatic cells–cells which are not passed from parent to child. However CRISPR has never been used in human embryos, and there are significant gaps in our knowledge about how the system would behave in an embryonic environment. CRISPR utilises a cell’s own DNA repair mechanism to modify strands of DNA, and it is unclear how the DNA repair mechanism in human embryos would interact with the CRISPR system. The study by Huang and co-authors aimed to fill this gap in the literature by seeing how effectively and efficiently CRISPR could make changes to DNA in human embryos.
This research is significant and important. Gene editing techniques like CRISPR could one day provide therapeutic cures to genetic diseases, and indeed completely eradicate diseases like Tay-Sachs, Huntington’s disease, and cystic fibrosis from our populations.
Of course there are significant risks associated with this type of research. Most significantly CRISPR could make off-target modifications in embryonic DNA and hence cause widespread damage to the genome. This could cause significant defects and disabilities in any individuals born as the result of the research. Because of these risks, it would be highly unethical to bring embryos to term who had been experimented on with current gene editing methods. The risk posed would simply not be justified by any potential benefits.
However this study by Huang and co-authors was not conducted in any embryos that were ever going to be born, or indeed even had the potential to be born. They trialled the CRISPR system in tri-pronuclear embryos–embryos that have a whole extra set of chromosomes. These embryos are not viable, and are normally spontaneously aborted early in pregnancy. These embryos were not created for this purpose, but were rather excess embryos created through IVF, and would otherwise have been destroyed. Trialling the CRISPR system in these embryos had no chance of resulting in a live birth. It is unclear how the study could harm or wrong anyone directly. Furthermore, this research is important precisely because it increases our understanding about some of the risks involved in targeting humans with current gene editing techniques. One of the stated aims of the research was to determine the frequency of off-target effects when CRISPR is used in human embryos. This type of research is important for increasing our understanding of the types of challenges involved in developing clinically useful methods of gene editing.
It is remarkable that the authors of the study report that they were denied publication on ethical grounds by both Nature and Science. This follows both these journals publishing commentary pieces calling for this type of research to be subject to a moratorium, or strongly discouraged. As we argued in a previous blog piece, the reasons given for this stance do not stand up to scrutiny. The commentaries allude to concerns about slippery slopes to non-therapeutic modifications, and unpredictable effects on future generations. These concerns are vague, emotive, and devoid of any real rational force. Many technologies have unpredictable effects and could potentially be used non-therapeutically. This doesn’t justify censorship of potentially life-saving research. Further, the timing of these commentaries might have influenced other journals to not to publish the research.
There are sometimes good reasons for not publishing research on ethical grounds. For example, a few years ago two separate studies used different methods to create a modified version of the deadly h5n1 bird-flu virus. The resulting viruses had an expected mortality rate of 60%, and could spread as easily as the common flu. The case for potentially censoring this research was clear. The methods used in the study could be utilised by terrorists to develop bioweapons which could potentially kill millions of people. Many called for the censoring of this research on ethical grounds. Nature published one of these studies and Science published the other , in revised forms in 2012.
The fact that Nature and Science deemed a study which changed DNA strands in a few non-viable embryos more of an ethical risk than studies which engineered a modified killer virus, should make us question the systems they have in place for assessing ethical risks. Both Nature and Science need to clearly explain the reasoning behind their decision not to publish this research.
Far from being wrong, the research by Huang and colleagues is ethically imperative. Such research not only has the potential to provide permanent cures for genetic diseases, it also holds the potential to correct the genetic contribution to common diseases like diabetes. It even has the potential to give people the capacity to age better–some extremely people age well into 90s and 100s. Age-related disease alone kills around 30 million people per year.
Imagine that I am a scientist. I have a promising candidate treatment that could save the lives of 30 million people per year. I decide not to continue the research. I am responsible for the deaths of those 30 million people if my research would have led to a cure.
One is left with the suspicion that religious reasons are behind the “ethical” justifications for not accepting this research. And scientists must be terrified by a Christian fundamentalist backlash against their research if they are connected in anyway with research on human embryos.
More than 100,000 fetuses are aborted every in the UK for social reasons, not for reasons of health. Healthy embryos are discarded routinely throughout the UK and US–yet valid scientific research capable of improving the lives of much of humanity is resisted because it involves a handful of embryos with lethal underlying genetic abnormalities.
It is the Chinese scientists led by Huang, not our leading scientific journals, who occupy the real ethical highground.