Coming soon — cut-and-paste children?
In the first successful test of a controversial technique, scientists in a new study were able to edit out heart disease-linked genes from fertilized embryos — with no adverse effects on the cells’ other genes.
Scientists at the Oregon Health and Science University used CRISPR, a controversial, but easy to use, gene-editing tool to remove bad genes from DNA.
“It’s the best way to treat the disease before the genetic mutation is actually transmitted to the embryo,” Dr. Shoukhrat Mitalipov, the project’s lead researcher, told Time Magazine.
Here’s how it works: Researchers led by Dr. Mitalipov took healthy human eggs and fertilized them with the sperm of a man with a genetic heart disease. Based on prior research, 50% of the embryos in the study were expected to carry the bad gene.
Scientists then deployed CRISPR, which consists of short, repetitive DNA sequences that can target undesirable gene sequences — like the mutated DNA segments that cause hypertrophic cardiomyopathy.
After CRISPR cut out those bad segments, the embryo itself repaired the cut. As a result, only 28% of the resulting embryos carried genes for hypertrophic cardiomyopathy.
The possibilities of CRISPR are as endless as the ethical qualms. Though it’s still in the testing phase, CRISPR has been likened to eugenics or playing God by allowing scientists to create “designer babies” or wipe out diseases through the kind of genetic engineering currently limited to plants and lower animals.
Last year, then-Director of National Intelligence James Clapper said CRISPR was potentially a weapon of mass destruction because of how easily it could be perverted into a weapon to create killer insects, plagues, or viruses.
Then again, the gene-editing tool could be used to eliminate horrific, costly diseases like cystic fibrosis, sickle cell anemia, certain cancers and heart diseases, and perhaps even offer protection against Alzheimer’s.
It will take a while for researchers to get to 100% effectiveness, at which point pregnancy trials may begin, pending government approval, which is by no means a sure thing.
There have been other successful attempts to edit human embryos carried out by scientists in China, but those experiments revealed errors in CRISPR’s ability to seamlessly edit DNA.
Mitalipov’s team may have finally found the fix.
“There is still work to do to improve the efficiency,” Dr. Mitalipov told Time. “But I think that’s possible to do.”