The past year has seen many developments in the field of gene editing, both in somatic and in germ line applications. Editing the germline means that changes will be made in every cell in the body and will be inherited by future generations. While carrying out such editing in a research setting is important for a greater understanding, clinical germline editing leading to a pregnancy carries considerable practical and ethical risks, at least at present.

The announcement of the birth of twins in China, following a procedure of germline gene editing performed by Dr He Jiankui, has attracted the attention of the international media, as well as raising serious concerns in the scientific community, and the Chinese authorities also condemned these procedures as being illegal in the country. A few scientists in the USA were informed about the intentions of Dr He Jiankui both before and during the course of his experiments. However, formal reports to ethics committees or other relevant institutions were never made. 

Now clinical germline gene editing has taken place, and the scientific community worldwide has been shaken and is questioning its responsibilities.

Over the past years, there has been a general consensus that it would be irresponsible to carry out any clinical germline gene editing at the present time, and that there is a need to promote research to build up a robust core of knowledge on the subject, as well as to explore more broadly the views of society on the scope and limits of this research and its potential future application. ESHG has contributed to these discussions and to this general consensus, notably through our Recommendations on Germline Gene Editing released in April 2018, and jointly signed with ESHRE.

Notwithstanding the wide scientific consensus on the inadvisability of clinical germline gene editing, clinical experiments have taken place. For this reason, a group of eminent scientists (Lander et al) has proposed that the scientific community should take a stronger position in the form of a moratorium on clinical, heritable, gene editing.

The moratorium would not prevent human germline gene editing research that will not lead to a pregnancy, neither will it discard the possibility of introducing germline gene editing in the future should nations so wish after adequate and thorough reflection, together with appropriate and sound international dialogue and supervision.

Such a moratorium will mean that every scientist pledges to adhere to a moral code of conduct according to which they will voluntarily refrain from and will not support any use of clinical germline editing - unless certain, clearly-defined conditions are met. These latter would entail a period of public notice of the specific intents, during which there would be robust international discussion about the pros and cons of doing so. Within individual nations there would also be debate to explore whether a broad societal consensus on whether to proceed with clinical human germline editing at all might be reached, as well as on the appropriateness of the proposed application.

The moratorium will also entail potential collaborators, ethics committees and peer-reviewed journals observing a ‘scientific embargo’. Such journals are the gatekeepers of trustworthy scientific communication across the world, and this requirement will involve more stringent ethical review and filtering.

As a scientific society with a commitment to contributing to the responsible translation of advancements in human genetics into a benefit for patients and society as a whole, we believe that it is our responsibility to make an unequivocal statement on this issue in response to the plea of our eminent colleagues, in order to provide clear direction to our members.

The ESHG, while considering fundamental and pre-clinical safety research on human germline editing to be not only justified, but necessary, supports the call for a global moratorium on all clinical uses of human germline editing - in sperm, eggs or embryos - that will lead to a pregnancy and/or to the creation of genetically modified children.

We urge relevant institutions to consider this plea for a moratorium in all their pertinent rulings, and to provide appropriate information to society as a whole so that adequately informed discussion may take place.