The child was conceived with the help of a USA medical team based in Mexico, along with a new in vitro fertilization (IVF) technique that helps parents with rare genetic mutations have healthy babies, according to New Scientist. Her two previous children died of the disease at 8 months and 6 years, the research summary said. It has only been legally approved for use in the United Kingdom.
Genes for this disease are found in DNA in the mitochondria, and about a quarter of her mitochondria have this Leigh syndrome mutation. Mitochondrial DNA is only passed down to children via mothers. The experimental procedure was done by New Hope Fertility Center of NY, which only now released the news, after weeks of waiting to see the outcome of the operation. Zhang had always been working on a “three-parent” method of conception called “spindle nuclear transfer”.
The three parent gene technique involves the removal of the nucleus from the mother’s fertilized eggs and moving it into a nucleus free egg, received from a donor who has healthy mitochondria.
John Zhang, a researcher at New York City’s New Hope Fertility Center, performed spindle nuclear transfer; he inserted the nucleus from the mother’s egg and placed it in the donor’s egg cell, from which he removed the native nucleus, making an oocyte that had the mitochondrial DNA of a non-related donor and the nuclear DNA of the mother.
Five embryos were created by Zhang and his team, but only one was able to develop normally – now the five-month old baby boy of the happy couple. This embryo was then implanted in the mother and the child was born nine months later. Also, a male embryo was used so that the resulting child could not pass on mitochondrial DNA.
The procedure was conducted in Mexico. According to Zhang, saving lives is the ethical thing to do.
However, fertility experts say it is important to push ahead, but cautiously. He told New Scientist that while the boy’s birth is “exciting news”, the child must be monitored going forward to make sure the faulty DNA doesn’t multiply and cause problems down the road.
The team will describe the findings at the American Society for Reproductive Medicine’s Scientific Congress in the U.S. in October.