The director of the Center for Neurology at the University of North Carolina, Mark Zilka, has led a team of scientists who have successfully completed genome editing in unborn mice. Their goal was to test the possibility of using the CRISPR-CAS9 tool to correct defects in genes that lead to the development of autism. The experiment showed good results, but this raises a very difficult question - how ethical is it to prepare a similar intervention in the genome of future human children?
Scientists have focused on counteracting Angelman syndrome, which leads to seizures, speech delays, and autism. It is caused by a mutation of the UBE3A gene on chromosome 15, which is passed on from the mother. Attempts to replace the incorrect gene with its edited version have failed due to unexpected side effects and complications. But this is the case with injections for children already born, but what if you try to carry out the procedure on embryos?
“The sooner the genome is edited, the better, ” says Zilka. His team operated on pregnant mice about three days before the birth of offspring, opening the brain of the embryos and injecting the prepared enzyme into it. This made it possible to turn off the defective gene and use a healthy paternal copy instead, so there were no deviations in the development of the body. But scientists still have little information about how such interference will affect the behavior of mice.
The idea of treating complex ailments while still in the womb, before the child's body is fully formed, is very tempting. But it is just as risky, because, in fact, scientists are entering a previously unknown field. They will have to be very careful when developing new techniques for manipulating human embryos.