Prometheus 6

Three-parent embryo formed in lab
Scientists believe they have made a breakthrough in IVF treatment by creating a human embryo with three separate parents.

The Newcastle University team believe the technique could help to eradicate a whole class of hereditary diseases, including some forms of epilepsy.

The embryos have been created using DNA from a man and two women in lab tests.

It could ensure women with genetic defects do not pass the diseases on to their children.

The technique is intended to help women with diseases of the mitochondria - mini-organs that are found within individual cells.

They are sometimes described as "cellular power plants" because they generate most of the cell's energy.

Faults in the mitochondrial DNA can cause around 50 known diseases, some of which lead to disability and death.

About one in every 6,500 people is affected by such conditions, which include fatal liver failure, stroke-like episodes, blindness, muscular dystrophy, diabetes and deafness.

At present, no treatment for mitochondrial diseases exists.