Scientists create three-parent embryos

Cloned embryo cells are seen in an undated file photo. British scientists have created a human embryo with three parents in a breakthrough they hope could lead to effective treatments for a range of serious hereditary diseases.

LONDON (Reuters) - British scientists have created human embryos with three parents in a development they hope could lead to effective treatments for a range of serious hereditary diseases within five years.

Researchers from Newcastle University, in northern England, presented their findings at a medical conference at the weekend, a university spokeswoman said on Tuesday.

The IVF, or test-tube, embryos were created using DNA from one man and two women.

The idea is to prevent women with faults in their mitochondrial DNA passing diseases on to their children. Around one in 5,000 children suffer from mitochondrial diseases, which can include fatal liver, heart and brain disorders, deafness, muscular problems and forms of epilepsy.

If all goes well, researchers believe they may be able to start offering the technique as a treatment in three to five years.

Mitochondria are tiny power packs inside cells that provide their energy. Faulty genetics can mean mitochondria do not completely burn food and oxygen, leading to the build-up of poisons responsible for more than 40 different diseases.

The Newcastle team believe these diseases could be avoided if embryos at risk were given an effective mitochondrial transplant. The process involves in vitro fertilization (IVF) and the subsequent removal of the egg's nucleus. The nucleus is then placed into a donor egg whose DNA has been removed.

The resulting fetus inherits nuclear DNA, or genes, from both parents but mitochondrial DNA from a third party.

"The idea is simply to swap the bad diseased mitochondria -- give a transplant, if you like -- for good healthy ones from a donor," Patrick Chinnery, a member of the Newcastle team, said in a telephone interview.

"We're trying to prevent kids being born with fatal diseases." Mitochondrial DNA is passed down only through the female line.

The technique has so far been tried only in the laboratory, using abnormal embryos left over from IVF therapy, and the handful of three-parent embryos created were destroyed after six days.

Stiff opposition to the technique is likely from critics of embryo research who fear the creation of designer babies.

The research was presented to the Medical Research Council Centre for Neuromuscular Diseases conference in London on February 1-2.

(Editing by Robert Woodward)