Scientists from the US, South Korea, and China have successfully altered genes in human embryos in order to correct a mutation that produces a serious heart failure disease, according to a recently published study.
The human embryos were edited in the US using the CRISPR method, which hallows experts to correct disease-bearing genes.
This achievement is a revolutionary breakthrough, and although it is still a long way from being approved for clinical use, it raises the possibility of editing genes to protect future babies from numerous hereditary conditions.
Specialists at the University of Medicine and Science of Oregon, along with their colleagues from California, China, and South Korea, were able to repair dozens of embryos by fixing a mutation that causes a common heart condition known as hypertrophic cardiomyopathy (HCM).
Researchers succeeded in successfully editing all the cells of the embryos and avoided creating extra unwanted mutations. If the embryos with the repaired mutations became babies, they would not only be cured of those diseases but would not transmit them to their offspring.
According to reports, this is the first time that human embryos have had their genomes edited outside of China, where scientists have already performed a handful of smaller studies.
“This embryo gene correction method, if proven safe, can possibly be used to prevent transmission of genetic disease to coming generations,” said Paula Amato, a fertility specialist involved in the US-Korean study at Oregon Health and Science University.
In the study published in the Journal Nature, scientists described how gene editing drastically reduces the number of embryos that carried dangerous mutations.
Furthermore, experts suggest that if performed early enough—around the same time as fertilization—72 per cent of the embryos were found to be free of the disease-carrying mutation.
“It feels a bit like a ‘one small step for (hu)mans, one giant leap for (hu)mankind’ moment,” Jennifer Doudna, a CRISPR pioneer from the University of California, Berkley, wrote in an email to The New York Times.
“I expect these results will be encouraging to those who hope to use human embryo editing for either research or eventual clinical purposes.”
This new study is revolutionary. In previous attempts, gene editing has only been partially successful due to various reasons like wrong genes being modified by mistake, or harmful mutations appearing in some cells. However, the latest work has shown how there is no evidence of these so-called “off-target-effects.”
Richard Hynes, a geneticist at MIT, said: “They’ve got remarkably good results, it’s a big advance.”
“This brings it closer to the clinic, but there’s still a lot of work to do.”