'Three-parent baby' treatment could be available on NHS from next spring

"Three-parent babies" could be born on the NHS in just over a year's time, after the controversial treatment looks set to get the go-ahead as early as next spring.

An independent panel of experts has cleared away remaining safety hurdles to recommend "cautious adoption" of mitochondrial replacement therapy (MRT) for devastating inherited diseases.

Following this, the UK fertility regulator, the Human Fertilisation and Embryology Authority (HFEA), is now almost certain to give the final go-ahead for the treatments.

The aim is to replace abnormal genes in the energy-producing mitochondria in the body's cells.

Mitochondria contain only around 0.1% of a person's DNA, which is always inherited from the mother and is quite separate from the DNA in the cell nucleus which houses the vast majority of an individual's genes.

But when mitochondrial DNA (mtDNA) goes wrong, the results can be catastrophic, leading to a wide range of potentially fatal conditions affecting vital organs, muscles, vision, growth and mental ability.

MRT involves removing faulty mitochondria and substituting healthy versions from a donor.

Babies born after MRT would effectively have three genetic parents. Their DNA would come from their mother and father, as well as a tiny proportion from an egg-donor.

MRT is carried out by transferring the genetic material that effectively encodes a baby's identity to the donor egg whose own nuclear DNA has been removed. Two different techniques can be carried out, either before or after fertilisation.

The end result is the same - an embryo containing healthy mitochondria from the donor and nuclear DNA from the baby's mother and father.

Scientists at the University of Newcastle, which has pioneered the treatments, say they already have women lined up for the therapy and are ready to apply for a licence to begin the procedures, and hopes to treat up to 25 women a year with NHS funding.

In theory, mitochondrial replacement can not only prevent a child developing inherited diseases, but also protect future generations.

The HFEA will consider the issue at a pivotal meeting on December 15, when it will decide whether clinics may make applications to offer the treatment.

If it agrees with the scientists, the first women could undergo mitochondrial replacement therapy as early as March or April next year.

Last year, the UK became the first country in the world to legalise mitochondrial replacement after MPs voted in favour of allowing it.

Assuming the HFEA invites clinics to make applications, each case will be considered on a patient-by-patient basis.

Mothers undergoing the untried procedure will effectively be human guinea pigs whose experiences will be written up in scientific journals, with their experiences used to develop the therapy.

Dr Andrew Greenfield, who chaired the expert panel and is an HFEA board member, said: "We think that the cautious approach to the use of mitochondrial donation in treatment that we recommend strikes the right balance between offering access to this exciting new treatment to couples at real risk of having a genetically-related child with mitochondrial disease, while doing all we can to ensure that the treatment is safe and effective."

Robert Meadowcroft, chief executive of Muscular Dystrophy UK, which supports families affected by mitochondrial diseases, said: "This pioneering technique could give women with mitochondrial disease the chance to have a healthy child, without the fear of passing on this condition which can lead to ... multiple disabilities and indeed life-limiting impairments."

However, not everyone is in favour of women receiving the treatments.

Dr David Clancy, from the faculty of health and medicine at the University of Lancaster, said the technique was "currently imperfect".

He argued that as many as one in 30 women receiving mitochondrial replacement therapy could give birth to a child with an inherited disease.