In a report released on 3 September, a group of experts from ten countries conclude that germline editing of human embryos is still too risky due to unresolved scientific and ethical issues.
The high-profile international commission, convened by the US National Academy of Medicine, the US National Academy of Sciences, and the UK Royal Society, reviewed the scientific and technical state of heritable gene editing and outlined the steps necessary before future attempts are made.
Germline editing can be defined as altering the DNA of a sperm or egg, or early embryo. While the technology has the potential to eliminate hereditary disease-causing mutations – which could, in theory, provide the only way for some couples to have a healthy child without serious genetic disease – the science is not yet advanced enough to ensure the edits will occur as intended.
Almost two years ago, the Chinese scientist, He Jiankui, shocked the medical world when he announced that a woman had given birth to two babies girls – twins – from embryos that had been ‘vaccinated’ using CRISPR-Cas9 to make them immune to the AIDS virus. The biophysics researcher – who was later jailed for three years for ‘medical malpractice’ and fined 3 million yuan (around €383,500) – used the gene-editing technique to first alter embryos, which were then implanted by in vitro fertilisation (IVF).
The news was met with almost universal condemnation, however, it was later revealed that a number of scientists around the world knew in advance of the Chinese scientist’s intention to start impregnating women with genetically modified embryos – but did not speak out or notify Chinese or international authorities, according to STAT.
Shortly after the world’s first gene-edited babies were born, many scientists called for a moratorium on germline editing to allow time for the international scientific community to develop the framework based on the important technical, scientific, medical, societal, ethical, and moral considerations.
The new report “is an important contribution” and offers “a framework for a potential translational pathway towards clinical application provided specific scientific, medical, and societal criteria could be fulfilled”, said the World Health Organization (WHO) committee in a statement. The WHO will use the report to inform a new system they are developing to govern genome editing research.
The much-anticipated report is comprised of 11 recommendations and introduces guidelines for germline editing, including the pre-clinical steps scientists should follow to demonstrate safety and efficacy before the procedure can be attempted in the clinic.
The first recommendation states that germline editing should not be carried out “until it has been clearly established that it is possible to efficiently and reliably make precise genomic changes without undesired changes in human embryos”. The authors also recommend that germline editing should only be attempted when parents have no other options of giving birth to a healthy child.
Moreover, they write that if germline editing is allowed in any country, it should only be used to fix mutations in single genes that cause diseases like cystic fibrosis, beta-thalassemia, sickle cell, and Tay-Sachs. The commission also recommends that any decision to allow germline editing should only be made after broad public discussions about the societal and ethical implications.
Finally, the report calls for “an international mechanism” through which researchers can raise a red flag if they suspect unethical genome editing is being performed or that “deviates from established guidelines or recommended standards”.
Just like many of the documents released over the past few years, the main takeaway is that germline editing is still far too premature and should only be attempted in the clinic once researchers can fully address the safety and ethical concerns.