3-parent babies: who’s eligible and what’s ethical?
With the announcement of the birth of the first baby using a controversial technique combining three people’s DNA, questions are swirling around exactly what the procedure entails.
The baby, whose mother was a carrier for Leigh syndrome, a type of mitochondrial disease, was born five months ago to Jordanian parents in Mexico, using a doctor from New York.
The treatment, which isn’t legal in the United States or Canada, involves removing some of the mother’s DNA (the nucleus) from an egg, and leaving the disease-causing DNA behind. The healthy DNA was slipped into a donor’s egg, which was then fertilized.
But it’s really only using small amounts of DNA from the donor; initial reports say she contributes less that one per cent of the resulting embryo’s genes.
“It more accurately might be described as a 2.05 parent baby,” Dr. Arthur Caplan, director of medical ethics at New York University, says.
Caplan says the mitochondria packets that are donated are basically battery packs to power the growth of a healthy baby.
“This little bit of heritable DNA did come along, but it doesn’t do anything important,” he explained in a phone call to Global News.
“They’re important, but they don’t make us who we are.”
Who’s eligible for it?
The only diseases this procedure can cure are mitochondrial ones, like Leigh syndrome, where there is a genetic mutation in the mitochondria. Since the nucleus of the egg is unchanged, most of the embryo’s genes aren’t changeable.
“It’s pretty rare,” Dr. William Bucket, the medical director at McGill University’s Health Centre said. “In 20 years I’ve maybe seen one person with mitochondrial disease and I can’t even remember the name of the disease.”
MitoCanada, a resource-based organization, said one in 5,000 people are affected by these types of diseases.
And doctors say there is no other case in which this specific treatment would help.
“Certain things that it won’t help are diseases that we know the genes that cause them, like cystic fibrosis and muscular dystrophy – those types of things,” Bucket said.
“The set of conditions [needed] are very small and not likely to expand,” Caplan said.
While Dr. Bucket said questions on whether this research could affect other types of infertility issues are being raised. The only country which legally allows this, the United Kingdom, restricts research to mitochondrial diseases.
Many people are wondering if a treatment like this could lead to other genetic modifications.
Health Canada prohibits “people from using genetic technologies to alter the DNA of embryos” to prevent “designer babies,” according to its website.
The specific technique is not approved in the United States, but the doctor who did the procedure John Zhang said, “To save lives is the ethical thing to do.”
And Caplan agrees: “this is clearly disease-oriented. This isn’t enhancement, improvement or eugenic in any way,“ he said.
“[It’s] a rare unusual technique that doesn’t really set a precedent.”
A spokesperson for The Canadian Medical Association declined to comment on the ethical concerns of the treatment.
*With files from Carmen Chai
© 2016 Global News, a division of Corus Entertainment Inc.