Back in April of this year, we wrote about the National Academies of Science and Medicine cautiously endorsing the possible use of gene editing at the germline level to correct serious diseases or medical conditions. Their report commented that scientists would likely be in a position to accomplish such activities safely within 5 to 10 years, and thus called for a careful consideration of the issues and ethics, as well as regulatory policies, surrounding the germline gene editing of humans.
Well, the future came a little closer this month. On July 26, MIT’s Technology Review broke the story that a research team at Oregon Health & Sciences University in Portland had used CRISPR to edit the genes of “many tens” of human embryos created using sperm from men carrying inherited genetic mutations. Unlike the three previous research efforts in China, the Oregon team reportedly achieved their results without seeing the off-target effects or mosaicism (i.e. when not all cells in an embryo exhibit the desired changes) that raised questions about CRISPR’s potential safety a few months back. The embryos were only permitted to develop for a few days and were never intended for implantation. And indeed, in the United States, any effort to turn such embryos into babies has been blocked by Congress, through language in a Health and Human Services funding bill that forbids the agency from approving clinical trials related to germline gene editing.
Further details of what the Oregon team has accomplished — and what questions will be raised about their work — will need to wait for the publication of the research in the coming months. But in any case, it appears the future of human germline editing has come a step closer.