When American scientists announced they’d conceived the world’s first “three-parent baby,” the world waited with bated breath for more details.
Now, for the first time, the doctors behind the controversial technique that combines DNA from three people are shedding light on their decision-making.
While global health officials are approaching the scientific milestone with skepticism, the scientists say they’re optimistic about the technique they’ve pioneered and ushered into the world.
“This is it. We did it, finally. This brilliant technology is exciting for mankind,” Dr. John Zhang, the lead author of the paper said in a press release.
His research was published Monday in the journal Reproductive BioMedicine. In the paper, Zhang and his team explain that they helped Jordanian parents conceive a healthy baby boy last April even though he was at risk of inheriting DNA for Leigh syndrome, a severe neurological disorder that usually kills within a few hours of birth.
They’ll have burning questions moving forward, though. Zhang’s paper concedes that the baby boy’s parents refused any further DNA testing on him unless it’s medically necessary.
Zhang’s team won’t know how the baby will fare moving forward and what the long-term implications may be from his novel conception.
But they explain how and why they tested out the experimental procedure. For starters, the baby boy’s mom lost two children to Leigh syndrome. His mother is a carrier of the genetic disorder but she’s asymptomatic. About one-quarter of her mitochondria passes on the genes for Leigh syndrome, the study revealed.
Zhang’s team implemented a new IVF technique using mitochondrial replacement therapy – or MRT. The technique involved removing the nucleus from a healthy donor egg and placing it into the egg cell of the mother in an attempt to weave out any risk of genetic issues.
The egg was then fertilized by the father’s sperm and transferred to his mother’s womb – the baby was born at 37 weeks after an “uneventful” pregnancy.
Tweaking the egg and fertilizing it were done in a private clinic in New York. The embryo was then frozen and taken to a clinic in Mexico where doctors met with the parents for implantation.
READ MORE: UK may allow babies with DNA from 3 people
“Now, for the first time, an egg with abnormal mitochondria can be changed to contain mostly normal mitochondria from a healthy egg donor. This is a major change of technology and an obvious advantage for women who are at risk of passing such diseases on to the next generation,” Bart Fauser, editor in chief of the journal, said in a statement.
For years, British and American health officials have been debating “three-parent babies” made from the DNA of a man and two women. It was dubbed as a medical breakthrough, a promising way to create babies free from certain diseases, but critics said this technology is playing God in making designer children.
Scientists believed that three-person IVF could help women who carry DNA mutations have healthy babies. With a third person’s DNA worked into the baby’s genes, defects like blindness or epilepsy won’t be passed on.
In initial reports, DNA from a donor egg amounts to less than one per cent of the resulting embryo’s genes. Essentially, the baby is made with the genes of the intended mother and father, with the help of the healthy mitochondrial DNA from the donor embryo.
By February 2015, the United Kingdom became the first country that allowed three-parent babies. So far, no other country has introduced laws to permit the technique.
The U.K.’s health minister at the time, Earl Howe, said the move offered “real hope” to families.
Because it’s “treating a disease,” medical ethicist Art Caplan says it’s fair game.
“These little embryos, these are people born with a disease, they can’t make power. You’re giving them a new battery. That’s a therapy. I think that’s a humane ethical thing to do,” Caplan, the director of medical ethics at New York University’s Langone Medical Center, told CNN.
What Caplan’s more concerned with is the “slippery slope” that might follow once health officials open the door to manipulating genetics to make a healthy baby.
“The big issue over the next five to 10 years is going to become how far do we go in pursuit of the perfect baby,” said Caplan.
Read Zhang’s full paper.