Interview: World's first baby born from new three-parent method "quite well": doctor
WASHINGTON, Oct. 19 (Xinhua) -- The world's first baby who was born six months ago using a new and controversial technique that incorporates DNA with three parents is now "lovely" and doing "quite well," his doctor told Xinhua.
The baby's birth in Mexico, where the three-parent method is not strictly regulated, was first reported by the New Scientist magazine two weeks ago, but John Zhang of the New Hope Fertility Center in New York, formally presented his findings Wednesday at the American Society of Reproductive Medicine's meeting in Salt Lake City.
"The boy is currently six months old. He is very healthy and doing quite well," Zhang said by phone from the meeting.
When asked if the boy eats, cries and sleeps just like other normal babies, Zhang said: "Yes, he is very lovely."
At issue is an IVF (in-vitro fertilization) technique called spindle nuclear transfer, which Zhang described as "revolutionary" and was designed to prevent women with devastating mitochondrial disease from passing them on to their children.
With this method, Zhang's team first removes the nucleus of the donor egg and replaces it with the nucleus from the mother's egg, thus creating an entirely new egg that is now comprised of DNA from two mothers.
This hybrid egg is then fertilized by the father's sperm to create an embryo, and if deemed normal the resulting embryo will be implanted into the mother.
Mitochondria are known as the powerhouse of cells and can only be passed on from the mother. Mutations in mitochondrial genes can lead to rare, serious diseases that are often fatal in childhood.
So far, Britain is the only country in the world to have authorized a three-parent technique called pronuclear transfer, which is performed after the egg is fertilized.
"A fertilized egg is considered a human life in many countries, and pronuclear transfer destroys two embryos, which frequently is at odds with the parents' religious beliefs," Zhang said, noting that his method solves the problem because it's performed before fertilization.
Zhang said that the six-month-old boy's parents from the Middle East sought their help in 2011 and since then they have been doing preparation work for this procedure, including making it safer and studying how to diagnose mitochondrial mutations.
"So we didn't do it in a hurry," he said. "We are very grateful to this patient, she is very brave, she trusts us, she is aware there are risks involved."
The mother of the boy carries genes for Leigh syndrome, a genetic disorder carried by the mitochondria of the cells that can lead to difficulty in swallowing, breathing, and ultimately, early death. She had four pregnancy losses and two deceased children at age eight months and six years from the disease.
Zhang's team created a total of five embryos for the couple, only one of which developed normally, which happened to be male. This embryo was implanted into the mother and the child was born nine months later.
A U.S. panel from the National Academies of Sciences, Engineering and Medicine has advised in February that the U.S. government should approve the three-parent IVF technique but one of the conditions is that the baby can only be a boy because males can't pass on their mitochondria to their children.
"We intentionally used the embryo, which happened to be male," Zhang said. "If the embryo was female, we would freeze and store it."
Zhang also responded to criticism that they should have submitted a paper for full peer review instead of announcing their results via media, saying they submitted a manuscript six months ago, but the problem they had was not technical, but rather ethical.
He predicted that the three-parent method could be widely accepted in 10 or 20 years, just as what the IVF technique, or commonly known as a test tube baby, has experienced in the past nearly 40 years.
"When the world's first test tube baby was born in the U.K. in 1978, about 80 percent of the time there was criticism, only 20 percent of the time was in favor," said Zhang. "But today we no longer think it's immoral. For any new technology, there is a process of acceptance."
While some experts hailed the study as heralding "a new era" in human reproduction, Professor Francoise Baylis, Canada Research Chair in Bioethics and Philosophy at Dalhousie University, said a key problem with the study is that this was done in Mexico without appropriate oversight.
"In fact, it would appear that the birth is the work of a maverick acting in defiance of efforts on the part of jurisdictions like the U.K. and the U.S. to move the science forward in a careful measured way that would be publically accountable," Baylis said in an email.[ Editor: Xueying ]