The post-lunch session is “Applications of Gene Editing Technology: Human Germline Modification”. Prior to hearing it I’m curious how cautious or gung-ho the speakers will be, or if their gestalt will be one of balance in the middle somewhere.
Robin Lovell-Badge, The Francis Crick Institute, was the moderator of this session. He said, “We’d be remiss in our duty if we didn’t discuss what was possible using human gene editing”, but “this doesn’t mean we think these should be done now” or that we advocate it being done now.
Peter Braude, King’s College London, spoke next. He started by talking about genetic risk. He also discussed preimplantation genetic diagnosis (PGD) a key, safe, powerful alternative to human genetic modification. Already by cleavage stage, some cells of embryos are different and there is mosaicism. This is a challenge to both PGD. Comment by Paul: this is a huge challenge to CRISPR’ing human embryos as well via mosaicism. Braude also summarizes reproductive situations where gene editing might be uniquely useful.
Kyle Orwig, University of Pittsburgh, focuses on spermatogonial stem cells (SSC). He said he hopes to convince the audience it may be possible to do germline gene editing to treat male infertility, which is a big statement. SSC can be maintained long term now, opening new doors including doing genetic modification of the cells.
George Q. Daley, Boston Children’s Hospital, presented possible medical indications where intervening in the embryo might be the only plausible, effective path to prevent disease, at least hypothetically. He pointed out the strong, human drive to find solutions to rare diseases, which is a great point. Further, the use of any new technology in people will carry risks. “One day germline human editing will be proven to work safely,” he said, which is one of the strongest statements of the meeting. He discussed a family case of “savior siblings” where PGD was successfully used to generate a new HLA matched sibling to be used to give a transplant to an existing child with serious illness. “I’m skeptical of Brave New World/Designer Baby scenarios. Most traits are too complicated genetically.”
George Church, Harvard Medical School, was up next. He always gets laughs from his intensely involved conflicts slide since he’s working with so many companies. He started with compelling medical applications for germline therapies including mitochondrial diseases (he notes to audience that he “doesn’t follow rules”) and complex diseases with single-target solutions. He also raised the key issue of equitable access to technology. It’s unclear how affordable human germline editing would be.
Azim Surani, Wellcome Trust Cancer Research UK Gurdon Institute, University of Cambridge spoke on human germ cells and induced pluripotent stem cells (IPSC).