A doctor who treats infertility in New York City says he has helped a couple have the first baby purposefully created with DNA from three different adults.
John Zhang of the New Hope Fertility Center in Manhattan traveled to Mexico earlier this year to perform a procedure for a couple from Jordan that enabled them to have the baby in May, according to a clinic spokesman.
Zhang performed the procedure in the hopes of helping the couple, who the clinic declined to identify, have a healthy baby. The couple had lost their first two children to Leigh syndrome, an inherited neurological disorder.
The idea of creating babies this way to help prospective parents who come from families plagued by genetic disorders has long been controversial. In February, a 12-member panel assembled by the National Academies of Sciences, Engineering and Medicine outlined a plan for how scientists could ethically pursue the research.
The Food and Drug Administration had requested the report after two other groups of U.S. scientists asked for permission to try. Despite the report, the FDA said Congress had prohibited the agency from allowing the procedure. In response to the latest development, the FDA reiterated that position in an email to NPR.
That prohibition had prompted Zhang to travel to Mexico, according to the clinic.
The baby's birth prompted both praise and criticism. Some infertility experts welcomed the development as a potentially important step for women carrying genetic disorders.
Zhang plans to present the details of the case at the society's meeting next month in Salt Lake City.
Some scientists said the move was irresponsible because not enough research had been done to know whether it was safe.
"This is a troubling development on a number of levels," wrote Paul Knoepfler, a cell biologist at the University of California, Davis, in an email to NPR. "It could have gone wrong in any number of ways and still could."
Others fear the move could open the door to the creation of so-called designer babies, in which parents try to pick and choose the traits of their children.
"This is entrepreneurial reproductive technology at its most unethical and irresponsible," wrote David King, who heads the genetic watchdog group Human Genetics Alert in London, in an email. "When are the world's governments going to stop rogue scientists crossing crucial ethical lines?"
One scientist hoping to perform this procedure in the United States is worried about details he has seen in Zhang's presentation.
"While exciting, there appears to be problems with the study," wrote Dieter Egli of Columbia University Medical Center in an email. Egli said he sees possible abnormalities in the embryos Zhang created, which he says reinforces why the FDA should be overseeing such experiments.
"For a technique pioneered and developed in the U.S., it be fitting to see the benefits to patients here as well," he says. "Because of funding restrictions to the FDA, promising medical advances are forced to move elsewhere."
The birth of the child was first reported Tuesday by the British magazine New Scientist. A clinic spokesman who asked not to be named told NPR that most of the details in the article were accurate except statements that the baby was born in Mexico and there was no oversight of the procedure there.
Leigh syndrome is known as a mitochondrial disorder because it is caused by defects in a type of DNA known as mitochondrial DNA. Mitochondria are structures in cells that provide the cells with energy.
To help women who carry defects in mitochondrial DNA, scientists have developed techniques to replace the defective mitochondrial DNA with healthy DNA.
The technique Zhang used involved removing all the DNA from the nucleus of eggs donated by women with healthy mitochondrial DNA. The DNA in the nucleus of eggs carries most of the genetic information needed to create a person, including the information most people consider important, such as determining an individual's physical appearance.
Zhang then removed all the nuclear DNA from the eggs of the woman trying to have a healthy baby and placed that DNA into the donor egg, leaving the defective mitochondrial DNA behind. Those eggs, which then presumably had only healthy DNA, were then fertilized with sperm from the husband of the woman trying to have a baby.
Zhang created five embryos this way. Only one developed normally, according to his report. It was transferred into the woman's womb and resulted in the birth of a boy, who appears healthy, according to the clinic.
Because mitochondrial DNA is only passed from women to their offspring, the boy is incapable of transferring the mitochondrial DNA to any future children, sidestepping many of the ethical concerns.
ARI SHAPIRO, HOST:
A fertility clinic in New York says it has created a baby with three genetic parents. The clinic says it did this for a family carrying a fatal genetic disorder. Joining us now to talk about this is NPR health and science correspondent Rob Stein. Hi, Rob.
ROB STEIN, BYLINE: Hey, Ari.
SHAPIRO: Tell us more about what the clinic says it did and why.
STEIN: Yeah. So the New Hope Fertility clinic in New York City says one of its doctors, John Zhang, Traveled to Mexico earlier this year to help a couple from Jordan who wanted to try to have a healthy baby.
The couple had lost their first two children to a terrible genetic disorder known as Leigh syndrome, or Leigh syndrome, which is a terrible neurological condition. So the doctor created an embryo in the laboratory using DNA from the parents trying to have a baby and from a third person to prevent that from happening again.
SHAPIRO: What can you tell us about how the doctor was able to do this?
STEIN: So you can kind of think of it as kind of a DNA transplant. You see, there are women like this woman in this Jordanian couple who are carrying these genetic diseases caused by defects in a particular kind of DNA. It's a very tiny part of DNA but important - called mitochondrial DNA.
And when you have defects in this DNA, it can cause these genetic disorders that are passed down for generations. So this doctor created eggs in the laboratory that replaced the woman's defective mitochondrial DNA with healthy mitochondrial DNA from eggs donated by another woman.
Then he fertilized those eggs in a laboratory just like you do with IVF. And he created embryos like this. So these embryos had mostly all the genes of the couple that were trying to have the baby - you know, the ones that we think are important, you know, eye color, how we look - that sort of thing - but a tiny little bit of DNA from another woman.
One of the embryos developed normally. It was implanted into the woman trying to have a healthy baby. And the baby was born nine months later, last May.
SHAPIRO: You had been following the research behind this for some time before this latest breakthrough. And one of the things you've been following is how controversial this is.
STEIN: Yeah, it's extremely controversial. The first big question is, is it safe? I mean - and a lot of people say, we just don't know yet. We haven't done enough basic research to know whether this is safe or not. Another question is how to think about kids born this way.
I mean, this baby and others, if they're ever created in the future, would have DNA from three different people, like I mentioned - from the woman who donated the healthy mitochondrial DNA, from the woman who's trying to have a healthy baby and from the husband.
So that raises all kinds of questions about identity, you can imagine. Like, these would be the first person - people - in the world like this. What would they - how would they think about themselves - who their parents are?
SHAPIRO: And then what about the longer term issues? As you play that forward, these kids potentially have children of their own and so on.
STEIN: Yeah. So, you know, another big concern is this involves making changes in human DNA that potentially could be passed down for generations. So what if they make cuts - do make some kind of mistake and create some new disease that's then passed down for generations and kind of mess up the human gene pool?
There's also the worry that doctors might try to do this sort of thing for nonmedical reasons and, like, try to create designer babies or that sort of thing.
SHAPIRO: Can you tell us how the baby's doing?
STEIN: So this was first reported by a British magazine called New Scientist. But I talked to the clinic this afternoon and confirmed all the details. And they told me that the baby is now about 5 months old and appears to be perfectly healthy. And he's a boy. So there's no chance that he could pass these changes on because mitochondrial DNA is only passed from mothers to their female offspring.
SHAPIRO: NPR health correspondent Rob Stein on a fascinating scientific breakthrough. Thank you, Rob.
STEIN: Oh, sure. Nice to be here.
[POST-BROADCAST CORRECTION: In the audio of this story, we incorrectly state that women pass mitochondrial DNA only to female offspring, rather than to all offspring.] Transcript provided by NPR, Copyright NPR.