UK scientists have won permission to create a human embryo that will have genetic material from two mothers.

The Newcastle University team will transfer genetic material created when an egg and sperm fuse into another woman’s egg.

The groundbreaking work aims to prevent mothers from passing certain genetic diseases on to their unborn babies.

Such diseases arise from DNA found outside the nucleus, and thus inherited separately from DNA in the nucleus.

Mitochondrial diseases

They are collectively called mitochondrial diseases.

Mitochondria are small complex structures, which exist in every cell of the body, except red blood cells. They are responsible for producing the energy that we need to grow and live.

One unique feature of mitochondria is that they have their own DNA – mitochondrial DNA, which is inherited from the mother only.

If this DNA is faulty, a mitochondrial diseases occurs. At present, no treatment for mitochondrial diseases exists.

Studies in mice show it is possible to prevent the transmission of mitochondrial disease by moving the pronuclei – the genetic material which will go on to form a nucleus – from a fertilised egg containing bad mitochondria and putting it into another fertilised egg which only contains good mitochondria.

Professor Doug Turnbull, professor of neurology at Newcastle University, and Dr Mary Herbert, scientific director of Newcastle Fertility Centre at the city’s Centre for Life, now plan to do the same in humans.

US scientists at the Institute for Reproductive Medicine and Science of St Barnabas, New Jersey, reported back in 2001 that they had successfully done similar, giving rise to 15 healthy children who appeared to be free of their mothers’ disease.

More here.