Controversial treatments to create so-called “three-parent babies” could be introduced in the UK in just a few months.
It comes after a panel of experts recommended “cautious adoption” of mitochondrial replacement therapy for devastating inherited diseases.
The technique could allow women who carry mutations in their mitochondrial genes – which generate energy in cells – to give birth to genetically related children free of mitochondrial disease.
But it is controversial as it would alter the DNA of an embryo in a way that could be passed on to future generations.
Britain’s fertility regulator the Human Fertilisation and Embryology Authority (HFEA) will meet in December and is highly likely to give the go-ahead in principle.
If it decides clinics can make applications for the treatment then the first women could undergo the untried procedure as early as next March or April.
A team at the University of Newcastle, which pioneered the work, hopes to treat up to 25 women a year with NHS funding.
The aim is to replace abnormal genes in the mitochondria. Fertility doctors would remove faulty mitochondria and substitute it for healthy versions from an egg donor.
Babies born after the treatment would effectively have three genetic parents – a mother, father and donor.
Mitochondria only hold around 0.1% of a person’s DNA, which is always inherited from the mother and has no influence over individual characteristics such as appearance and personality.
It is separate from the DNA in the cell nucleus which house 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, which are said to affect one in 4,000 people.
Muscular Dystrophy UK supports families affected by mitochondrial diseases.
Chief executive Robert Meadowcroft 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 Dr David Clancy, from the faculty of health and medicine at the University of Lancaster, said the technique was “currently imperfect”.
He claimed the risk of carry-over and reversion could lead to as many as one in 30 women receiving mitochondrial replacement therapy giving birth to a child with an inherited disease.