The British government has begun public hearings to look at the issue of three-parent Invitro-Fertilisation (IVF) babies, to prevent disease, while raising the ethical issue of genetic modification.

The BBC explains, the technique, which implants the modified fertilised- egg from one couple into the egg of another woman, could be used to prevent, the sometimes fatal, "mitochondrial" diseases which are passed down from mother to child.

The mitochondria provide energy to every cell in the body, but about one in every 200 children is born with faulty mitochondria. Most will be born with few or no symptoms but in the most extreme cases, the cells of the body don't recieve energy which leads to muscular dystrophy, blindness, heart failure and sometimes death.

The Telegraph says the technique would pass along only a small fraction of the DNA from the donor but would prevent future generations from rare and debilitating conditions.