CRISPR, like IVF and other technologies before it, raises the specter of the creation of "designer babies," writes Philip Ball at the Guardian.
Though CRISPR/Cas9 is being explored as a way to modify disease-causing genes, there's the concern that the tool could be used for non-therapeutic purposes, he adds. But a number of researchers and ethicists don't think CRISPR-driven human reproduction will be a concern anytime soon as it's too expensive and has unknown health risks.
Instead, Stanford University's Hank Greely tells Ball that pre-implantation genetic diagnosis coupled with embryo selection is the current most plausible route for the development of "designer babies." Such an approach is already used by a small percentage of couples seeking in vitro fertilization to screen for diseases like thalassemia or cystic fibrosis. Even this approach, though, isn't a good way to "design" babies, Greely tells Ball, as it requires egg harvesting, which is risky and doesn't yield that many eggs. However, he adds that will change with developments in the field and with cheaper genome sequencing.
Still, Ball notes that many traits have turned out to be more complicated than initially assumed — numerous genes influence, for instance, diabetes risk and little is known about genes that may affect intelligence. Designing, then, may be limited and give probabilistic predictions like that a child would have a 60 percent chance of being in the top half at school, he adds.
While Greely predicts it'll take a few decades for gene editing and reproductive tools to be used for genetic enhancements, Alta Charo from the University of Wisconsin tells Ball that it may never become common for people who aren't facing serious diseases or infertility. "[W]e already have evidence that people do not flock to technologies when they can conceive without assistance," she says.