Genetic engineering has, for a long time, been a highly heated and contested issue. One must weigh the ethical ramifications and risks of engineering human embryos with the huge potential health benefits that this technology may bring to the medical community.
This practice can sometimes lead to errors that could potentially result in permanent problems in the human gene pool, and bioethicists fear that this technology could spiral into customizing our own “designer babies” with specific desirable traits.
However, a precise gene-editing tool called CRISPR has been used before to edit human embryos, but only in China.
In the United States, in light of all of the controversy, the NIH has banned using funding to research this kind of technology. That being said, in February, a committee created by the National Academy of Sciences and the National Academy of Medicine went back and endorsed genetic engineering on human embryos in the absence of a “reasonable alternative,” i.e. only for the most severe of diseases.
Thus, regardless of your stance, factually, being able to edit human DNA is the very first step toward preventing incurable diseases and disabilities, but even so, the prospect of engineered humans still seemed more like science fiction than actual science.
Until now.
In a story originally reported by MIT Technology Review, and picked up by The Verge, announced that American scientists have successfully edited the DNA of viable human embryos for the very first time using CRISPR, only pulling us further away from science fiction.
This research was led by Shoukhrat Mitalipov of the Oregon Health and Science University, and it involved editing dozens of viable embryos to correct a particular gene mutation responsible for hypertrophic cardiomyopathy, a heart disorder that can lead to sudden death. These embryos were developed for only mere days, using the sperm of a man with the hypertrophic cardiomyopathy gene mutation, and ultimately, they never were implanted and didn’t develop into babies.
Mitalipov’s team succeeded in editing these genes without any undesired mutations, with another breakthrough: the male gene copied the healthy sequence from the female gene after being altered, showing that the embryos repair themselves in a way that was previously unknown.
This avoided mosaicism in the embryos’ cells, which occurred in previous Chinese experiments.
(Mosaicism occurs when the DNA changes are only picked up by some cells, but not all of the cells in an embryo. It makes gene-editing very unsafe.)
The technique isn’t perfect yet, and there are more concerns that need to be worked out before genetic-engineering in humans advances any further.
Nonetheless, these breakthroughs prove just how much we have advanced on this front, truly making “one step for (hu)mans, but one giant leap for (hu)mankind.”
-Jennifer Doudna, CRISPR pioneer
