On January 5, a baby was born with the DNA from three parents—the second in the world. Doctors from the Nadiya Clinic in the Ukrainian capital Kiev announced that the baby girl was produced with a technique called pronuclear transfer, used to treat infertility. But the move is stirring up controversy in the medical community, reports Michelle Roberts at the BBC.
While “three-parent” babies may sound like a concerning step towards genetically modified humans, there’s a legitimate medical reason for the procedure. The treatment was designed to help mothers suffering from a disease of the mitochondria—the organelles that serve as a cellular “powerhouse”—give birth to children without passing down the condition.
During the procedure, doctors fertilize an egg from the mother with the mitochondrial dysfunction with the sperm from the father. That embryo nucleus is then removed from the egg and implanted into a healthy egg from a donor. Susan Scutti at CNN reports that the resulting child receives the bulk of its 20,000 to 25,000 genes from its parents. About 37 genes, which regulate mitochondria, come from the donor egg, technically giving the child genetic material from three people.
Last year, a couple from Jordan who had lost two daughters to Leigh syndrome, underwent a similar procedure called spindle nuclear transfer. It was performed in Mexico by U.S. doctor John Zhang since the procedure is not currently legal in the United States. The couple gave birth to a healthy boy, whose gender was selected to prevent him from passing along the altered genes (mitochondrial DNA comes only from the mother).
The Ukrainian procedure, however, is stirring controversy. It was used as general treatment for infertility—not as a work around for mitochondrial disease, Scutti reports. The couple also gave birth to a girl, meaning that she will pass along the donor mitochondrial DNA if she has children.
The mother in question had been unable to get pregnant for 15 years. Using the procedure as an IVF technique allows doctors to bypass cells or enzymes in the mother’s egg that might prevent pregnancy or hinder cell division, explains Andy Coghlan at New Scientist.
Though Great Britain voted to allow the procedure for mitochondrial problems in February 2015, this is the first test of the method as an IVF technique. Adam Balen, chairman of the British Fertility Society tells Roberts that the latest use of the treatment is concerning. “Pronuclear transfer is highly experimental and has not been properly evaluated or scientifically proven,” he says. “We would be extremely cautious about adopting this approach to improve IVF outcomes.”
Valery Zukin, director of the Nadiya Clinic tells Scutti that a medical review board approved the procedure and that a thorough genetic screening was performed before the treatment. “In Ukraine, the situation is very simple—it’s not forbidden,” Zukin tells Scutti. “We have not any regulation concerning this.”
Zhang, who performed the first three-parent treatment last year, tells Scutti he’s not too concerned about the couple having a female child as long as the mitochondria are healthy. But he does have a few problems with the procedure. First, he says using the treatment on a healthy 34-year old woman is probably not appropriate and that statistically it was likely she could get pregnant without IVF. Secondly, Zukin used a virus protein to facilitate the procedure, which will integrate the virus into the baby’s DNA. Zhang says using electronic techniques are the current standard.
According to Roberts, Zukin has a second patient who received the treatment and is scheduled to give birth in March.