The UK has become the first country in the world to legalise the creation of IVF babies using DNA from three people.
The move was backed by the House of Lords and means that we could see the first baby conceived with mitochondrial donation techniques could be born as early as 2016.
It will enable a couple to use DNA donated by another woman in cases where the mother carries inherited mitochondrial diseases, which can be fatal.
A Department of Health spokeswoman said: “Parliament’s decision will bring hope to hundreds of families affected by mitochondrial disease.
“We are proud to be the first country to allow these revolutionary techniques. For the first time ever, women who carry severe mitochondrial disease will have the opportunity to have healthy babies without the fear of passing on devastating genetic disorders.”
The technique, developed in Newcastle, will help to prevent genetic diseases being passed from mother to child.
It offers hope for some women to have healthy genetically-related children.
Research has shown that almost 2,500 women of reproductive age in the UK will benefit from mitochondrial donation.
Alastair Kent, Director of the Genetic Alliance UK charity, said: “The vote in the House of Lords is a triumph that gives hope to families who otherwise would have to face the prospect of not being able to conceive a child free from a life-limiting disease.”
Children conceived after mitochondrial donation would have “nuclear” DNA determining individual traits such as facial features and personality from its two parents, plus a tiny amount of mitochondrial DNA from an anonymous woman donor.
Before the official vote, the change in law was been backed by chief medical officer Dame Sally Davies.
She said it would “give these women their own children and these families hope, and I believe this is right”.