'Three parent embryos' created from human eggs

Embryos containing DNA from three parents have been created from human eggs for the first time in a breakthrough for a therapy which could eradicate a host of rare genetic disorders.

Eggs containing DNA from two women were fertilised and grown into healthy embryos in a lab experiment by researchers from Oregon Health & Science University in the US.

The technique is designed for women who have mutations in tiny structures known as mitochondria, which can result in a range of devastating conditions including muscular dystrophy.

It involves taking chromosomes from the mother's egg, which carry 99.8 per cent of her DNA, and placing them in a donor egg which has healthy mitochondria but has had its own chromosomes removed.

The eggs were fertilised by sperm and almost half developed into healthy embryos. The resulting children would have inherited 99.8 per cent of their DNA from their parents, but also a tiny fraction from the donor.

Writing in the Nature journal, the researchers reported that half of the embryos developed abnormally, but identified improvements in their technique which could improve its success rate.

The Telegraph