The White House draws the line against CRISPR/Cas9-designed embryos

Fretting over the implications of reengineering human embryos with new CRISPR/Cas9 gene editing technology, officials at the White House have weighed in to the growing controversy, saying that "altering the human germline for clinical purposes is a line that should not be crossed at this time."

CRISPR/Cas9 has become an overnight sensation in the biotech world, promising to give drug developers new technology for editing diseases out by altering their DNA. Academic groups were quick to follow up on the biotechs with their own projects, while raising an alarm that the technology could be applied to embryos--a prospect that raised a storm of debate over the ethics of genetically redesigning humans.

Just weeks ago, a group of Chinese investigators in Guangzhou highlighted those concerns, noting that they tried to edit out the gene responsible for the lethal blood disorder β-thalassaemia in nonviable embyos. And even though they encountered some major problems, top investigators quickly criticized the project, raising fears that these inheritable genetic changes could lead to unknown results as well as opening the door to future enhancements on future generations of humans.

"I believe this is the first report of CRISPR/Cas9 applied to human pre-implantation embryos and as such the study is a landmark, as well as a cautionary tale," Harvard's George Daley told Nature in April. "Their study should be a stern warning to any practitioner who thinks the technology is ready for testing to eradicate disease genes."

"Research along these lines raises serious and urgent questions about the potential implications for clinical applications that could lead to genetically altered humans," noted Dr. John Holdren, director of the White House Office of Science and Technology Policy. "The full implications of such a step could not be known until a number of generations had inherited the genetic changes made--and choices made in one country could affect all of us."

The National Academy of Sciences is convening an international meeting this fall to discuss the technology's use on embryos.

- here's the statement