DNA of human embryos edited for 1st time in US – report
Led by Shoukhrat Mitalipov, a team of scientists at the Oregon Health and Science University used the CRISPR-Cas9 genome editing technology to alter human DNA in single-cell embryos, according to a report published Wednesday on the MIT Technology Review.
“So far as I know, this will be the first study reported in the US,” Jun Wu, a collaborator at the Salk Institute, told the MIT Technology Review.
The report claims that Mitalipov broke new ground “both in the number of embryos experimented upon and by demonstrating that it is possible to safely and efficiently correct defective genes that cause inherited diseases.”
The team used donated sperm from men who carried inherited disease mutations to demonstrate that the genes can be corrected. Although the report said that “many tens” of embryos were created in the experiment, they were never intended to be implanted into a womb and were only allowed to develop for a few days.
To eradicate the disease, Mitalipov and his team used a process called “germline engineering,” in which genetically modified organisms pass changes to their offspring.
Earlier publications by scientists in China found that CRISPR caused editing errors known as “mosaicism,” in which some cells in the embryo did not take the desired changes. However, Mitalipov said his team was able to avoid mosaicism by injecting CRISPR into the eggs at the same time they were fertilized with sperm.
The technique was previously tested by Tony Perry, who was able to successfully edit the genes in mice to change the expected fur color of their offspring.
A scientist familiar with Mitalipov’s project said the tests were “proof of principle that it can work.”
“They significantly reduced mosaicism. I don’t think it’s the start of clinical trials yet, but it does take it further than anyone has before,” an unnamed scientist told the MIT Technology Review.
Mitalipov did not confirm the results of the test, telling the MIT Technology Review that they are still “pending publication.” However, if his research passes peer review it could be a significant step for scientists in the US.
Successfully editing genes in human embryos could theoretically lead to scientists being able to cure any number of diseases, including cancer.
To date, there have only been three previous reports of editing human embryos, all of which were published by scientists in China.
Federal regulations have barred scientists in the US from any efforts to turn an editing embryo into a baby. Many critics are worried that the practice could lead to “designer babies” that are engineered with genetic enhancements.
Last year, the Office of the Director of National Intelligence released a report that added genome editing to a list of weapons of mass destruction and proliferation, saying it “increases the risk of the creation of potentially harmful biological agents or products.”
In February, the US National Academy of Sciences released a report, endorsing the use of gene editing, but only for “serious conditions under stringent oversight.”