American and South Korean scientists have successfully removed a part of the genome of human embryos using CRISPR-Cas9 to eradicate a hereditary heart disease, according to a study published in Nature yesterday.
Scientists from Oregon Health and Science University and the Salk Institute in the US, and the Institute for Basic Science in South Korea have used this technology for the first time to successfully eliminate a specific gene in human embryos that causes hypertrophic obstructive cardiomyopathy causes.
This hereditary heart disease occurs in about 1 in 500 people and can cause sudden cardiac arrest. Those who carry the gene have a chance of 1 in 2 to pass on the disease to their children.
72 percent succes rate
With CRISPR, the scientists managed to eliminate the gene responsible for hypertrophic obstructive cardiomyopathy during fertilization. The scientists injected sperm cells from a man carrying the gene in healthy egg cells, along with CRISPR technology. Then they allowed the embryos to grow for 5 days. Ultimately, 72 percent of the embryos did not seem to carry the gene.
Although the scientists destroyed the embryos for ethical reasons, the babies most likely would never have developed the heart disease and also would not have passed it on to their children.
It's not the first time that scientists use CRISPR in the hope to eliminate genetic defects. In 2015, Chinese scientists also reported that they manipulated human embryos using CRISPR with the aim to avoid a hereditary blood disease. The results were less satisfactory, amongst other things, because the technique had "inadvertently" affected other genes.
In contrast, in the current study, the scientists managed to only edit the genes that cause hypertrophic obstructive cardiomyopathy. The other genes remained untouched.