Aliasgharson, Wikimedia Commons.
Well it was bound to happen sooner or later: Chinese scientists reported the first attempt to modify (design) the genome of human embryos. The group of Junjiu Huang at Sun Yat-sen University in Guangzhou published in Protein & Cell that they alter the human genome using CRISPR/Cas9 technology. This is the first step to being able to correct disease (which is what they were trying to do) or make designer babies.
This is obviously kind of a bit very controversial which the Huang attempted to address by using non-viable embryos. Specifically, they used "tripronuclear zygotes": eggs that were fertilized by two sperm simultaneously, which apparently happens in around 7% - 8% of IVF embryos. Such embryos have three nuclei total (two sperm pronuclei and one oocyte nucleus) and, while it's true they won't normally develop, it seems it's also possible to suck out the extra one and have a normal human birth. (Note the sucking process unfortunately kills most of the embryos though.)
The ethical dimensions of genome editing are, shall we say, broad and the concerns many. Most significantly, these are germline modifications, which means the changes will be passed to any children of those who were modified.
Dolly, the world's first cloned sheep, now stuffed at the National Museums of Scotland. Mike Pennington, Wikimedia Commons.
All that said, editing isn't exactly working very well right now: of 86 embryos injected using various experimental conditions, only 4 lived and were edited as intended. Now a 4.65% success rate isn't exactly a super good bet but maybe there's some situation where people would do that. Except, the research also revealed "notable off-target effects" or editing where it's not supposed to be edited. In addition, the study "likely underestimated the off-target effects" because it sequenced a portion of the genome, the exome. [One can kind of think of the exome as a TV show with segments you'd ignore, maybe ads, removed with the rest spliced together. That's a pretty bad analogy but suffice it to say the information of our genes has "extra pieces" interspersed with the "real pieces." This study looked only at the "real pieces" and thus underestimated the occurrence of unintended editing.] As Huang commented, “If we did the whole genome sequence, we would get many more.”
They summarize: "Further investigation of the molecular mechanisms of CRISPR/Cas9-mediated gene editing in human model is sorely needed. In particular, off-target effect of CRISPR/Cas9 should be investigated thoroughly before any clinical application." Indeed.
Remember Dolly, the cloned sheep who developed severe arthritis and progressive lung disease? Cloning is arguably way easier than editing and I'd hate to be the person who got editing 1.0. All of the above said, we've already opened Pandora's box; this will I think inevitably be applied to people, be for good or bad.
As for cloning, China is now "cloning on an 'industrial scale'." As the Chief Executive of the industrial cloning company said, "if it tastes good you should sequence it... you should know what's in the genes of that species" apparently so we can soon just edit all pigs to taste perfect. Of note, my parents traveled to China. The thing that stood out to my father? "I've never had bacon that tasted as good."