Three-parent children may be born in near future in an effort to combat mitochondrial diseases

By Dr. Ananya Mandal, MDJan 22 2012

In the next couple of years the scientific community may witness creation of children with genetic material from three parents. British scientists want to start testing a new IVF technique to try to eradicate incurable genetic diseases such as muscular dystrophy. The concept took a leap forward yesterday after the Government announced a public consultation on whether the law should be changed to allow the technique.

The experimental process involves taking healthy DNA from a mother’s egg – either before or after fertilization – and transferring it into an egg donated by another woman. This egg is then implanted into the mother to avoid passing on faults in her mitochondria, the tiny ‘batteries’ which power cells. In theory the child would then have genetic material from its mother, father and the donor. However, it would not inherit the donor’s characteristics.

Mitochondria are sausage-shaped powerhouses which float around inside cells converting food into energy the body can use. Each contains a tiny strand of DNA – around 37 of the 23,000 human genes – which is passed on by the mother. But mutations of this DNA – which is only involved in generating energy – can cause around 50 serious and untreatable genetic diseases. These affect around one in 5,000 children, causing symptoms such as blindness, deafness, heart and kidney problems and early-onset dementia. Many sufferers die before reaching adulthood.

The idea raised a virtual ethical storm with warning that it is creating ‘hybrid’ children and could have unknown risks for future generations but Science Minister David Willetts said that the researchers had made an “important and potentially life-saving  discovery” but it was important to get the regulation right. Josephine Quintavalle, of the pro-life campaign group Comment on Reproductive Ethics, said, “Mitochondrial disease is obviously serious and worrying but it does not merit experimenting on humans and unleashing who-knows-what on the next generation. It’s like we’ve written off the laws of nature.”

Professor Doug Turnbull, of Newcastle University, who pioneered the technique, said he believed the first patients would begin treatment in two to three years. “This has the possibility of stopping the disease and stopping it in the next generations as well…Every year we see hundreds of patients whose lives are seriously affected by mitochondrial diseases. We want to make a major difference to their lives. This has the possibility of stopping disease and stopping it in the next generations as well.”

Alastair Kent, from Genetic Alliance UK, said that the impact of mitochondrial disease could be “devastating”. He said, “It will be quite a long time before this is available as a clinical service, and our primary concern is to make sure the technique is safe. But it would be sensible and reasonable to offer it to prevent these conditions.”

The public consultation on changing the law will begin this year and will be voted on by MPs. Last April the Government’s fertility watchdog, the Human Fertility and Embryology Authority, produced a report on the technique, which found it was safe but recommended more tests. DNA transfer has been done internationally on many different animals including primates, but never humans.

Robert Meadowcroft, of the Muscular Dystrophy Campaign, which has donated £1.2million into researching mitochondrial disease, said, “This could end the heartbreak of parents passing on these diseases to their children. It has been shown to work in the lab so now we must move it into clinical trials without delay.”

Yesterday the Wellcome Trust, a private funding body, announced a £4.4million grant to the university for a mitochondria study centre. Sir Mark Walport, from the Wellcome Trust, said the technique might prevent previously incurable diseases. “We welcome the opportunity to discuss with the public why we believe this technique is essential if we are to give families affected by these diseases the chance to have healthy children, something most of us take for granted.”