22 March 2015

Editing Embryos

Three calls to restrict the use of genome-editing tools to modify the DNA of human embryos.

In 'Don’t edit the human germ line' Edward Lanphier, Fyodor Urnov, Sarah Ehlen Haecker, Michael Werner and Joanna Smolenski in Nature comment
It is thought that studies involving the use of genome-editing tools to modify the DNA of human embryos will be published shortly.
There are grave concerns regarding the ethical and safety implications of this research. There is also fear of the negative impact it could have on important work involving the use of genome-editing techniques in somatic (non-reproductive) cells.
We are all involved in this latter area of work. One of us (F.U.) helped to develop the first genome-editing technology, zinc-finger nucleases (ZFNs), and is now senior scientist at the company developing them, Sangamo BioSciences of Richmond, California. The Alliance for Regenerative Medicine (ARM; in which E.L., M.W. and S.E.H. are involved), is an international organization that represents more than 200 life-sciences companies, research institutions, non-profit organizations, patient-advocacy groups and investors focused on developing and commercializing therapeutics, including those involving genome editing.
Genome-editing technologies may offer a powerful approach to treat many human diseases, including HIV/AIDS, haemophilia, sickle-cell anaemia and several forms of cancer. All techniques currently in various stages of clinical development focus on modifying the genetic material of somatic cells, such as T cells (a type of white blood cell). These are not designed to affect sperm or eggs.
In our view, genome editing in human embryos using current technologies could have unpredictable effects on future generations. This makes it dangerous and ethically unacceptable. Such research could be exploited for non-therapeutic modifications. We are concerned that a public outcry about such an ethical breach could hinder a promising area of therapeutic development, namely making genetic changes that cannot be inherited.
At this early stage, scientists should agree not to modify the DNA of human reproductive cells. Should a truly compelling case ever arise for the therapeutic benefit of germ­line modification, we encourage an open discussion around the appropriate course of action.
'A prudent path forward for genomic engineering and germline gene modification' by David Baltimore, Paul Berg, Michael Botchan, Dana Carroll, R. Alta Charo, George Church, Jacob E. Corn, George Q. Daley, Jennifer A. Doudna, Marsha Fenner, Henry T. Greely, Martin Jinek, G. Steven Martin,Edward Penhoet,Jennifer Puck,Samuel H. Sternberg,Jonathan S. Weissman, Keith R. Yamamoto, in Science argues that
A framework for open discourse on the use of CRISPR-Cas9 technology to manipulate the human genome is urgently needed.
The authors go on to recommend
  • Strongly discourage clinical application of this technology at this time. 
  • Create forums for education and discussion 
  • Encourage open research to evaluate the utility of CRISPR-Cas9 technology for both human and nonhuman model systems. 
  • Hold an international meeting to consider these issues and possibly make policy recommendation. 
That's consistent with the International Society for Stem Cell Research policy statement on human germline gene editing, which calls for a ban on clinical application of human germline gene editing technology but is less restrictive on laboratory activity.

calls for a moratorium on attempts at clinical application of nuclear genome editing of the human germ line to enable more extensive scientific analysis of the potential risks of genome editing and broader public discussion of the societal and ethical implications.