The bacterial enzyme Cas9 is the engine of RNA-programmed genome engineering in human cells.
Image credit: Jennifer Doudna/UC Berkeley
"Given the speed with which the genome engineering field is evolving," write the authors of the article, "our group concluded that there is an urgent need for open discussion of the merits and risks of human genome modification by a broad cohort of scientists, clinicians, social scientists, the general public and relevant public entities and interest groups."
Warnings over the potential misuse of genetic engineering have been issued several times since the inception of the technology in the 1970s. However, until now, the technology to fix genetic defects had not been easy to use.
The scientists write that "this limitation has been upended recently by the rapid development and widespread adoption of a simple, inexpensive and remarkably effective genome engineering method known as CRISPR-Cas9."
"The simplicity of the CRISPR-Cas9 system enables any researcher with knowledge of molecular biology to modify genomes, making feasible many experiments that were previously difficult or impossible to conduct," they explain.
The warning from the scientists has added gravity due to the presence of Jennifer A. Doudna among the team - the co-inventor of CRISPR-Cas9.
Genome engineering technology should be 'performed safely and ethically'
As Doudna and her colleagues are still perfecting the technology that will allow genetic changes to be precisely targeted, she and the other authors wrote the Science article to:
"[...] initiate an informed discussion of the uses of genome engineering technology, and to identify proactively those areas where current action is essential to prepare for future developments. We recommend taking immediate steps toward ensuring that the application of genome engineering technology is performed safely and ethically."
Currently, CRISPR-Cas9 is being used to correct DNA sequences in animals and cultured tissues generated from stem cells. It is expected that these techniques can also be successfully applied to humans. Play the video below to find out more about the invention.
However, the authors are concerned that making changes to "germline cells" in sperm or eggs that can be passed on to offspring could have unintended consequences, as our knowledge of human genetics is still limited.
They write that "scientists should avoid even attempting, in lax jurisdictions, germline genome modification for clinical application in humans" until the full implications "are discussed among scientific and governmental organizations."
"You could exert control over human heredity with this technique, and that is why we are raising the issue," co-author Dr. David Baltimore, a former president of the California Institute of Technology, told The New York Times.
"We worry about people making changes without the knowledge of what those changes mean in terms of the overall genome," added Dr. Baltimore. "I personally think we are just not smart enough - and won't be for a very long time - to feel comfortable about the consequences of changing heredity, even in a single individual."