A new IVF technique which, if approved, could stop children from inheriting severe diseases by replacing faulty DNA with genetic material from a donor.
The new technique has been developed specifically to prevent mitochondrial disease, an umbrella term for a number of severe medical disorders caused by genetic mutations in mitochondria (the 'batteries' that power every cell in the body).
These disorders include muscular dystrophy, ataxia - and Leigh's disease, a disorder that has killed every one of Sharon Bernardi's seven children.
Scientists at Newcastle University are developing the new technique. It uses IVF technology to transfer genetic material between the mother's egg and a donor egg, to ensure the child won't develop the disease. Only a tiny proportion of the child's DNA - less than 1 per cent - will come from the donor.
However, some critics say the technique should not be be permitted because a child born this way would have 'three parents'.
The UK government has launched a public consultation on whether doctors should be allowed to use this technique to treat affected families or not?
The Wellcome Trust, a medical research charity which is funding the Newcastle scientists, has invited experts Professor Doug Turnbull, who is developing the technique at Newcastle University and Susan Golombok, a University of Cambridge expert on the impact on families of using techniques such as IVF, to answer questions (See: Q & A on using IVF techniques to prevent mitochondrial disease).