A County Durham mother is waiting for permission to have a baby which, thanks to genetic engineering, can save her son's life.

Chester-le-Street woman Michelle Whitaker and her husband Jayson want to follow in the footsteps of a Leeds couple who have been grated permission by the Human Fertilisation and Embryology Authority (HFEA) to conceive a baby to cure their seriously ill son.

Three-and-a-half-year-old Charlie Whitaker suffers from a rare and deadly condition which means his bone marrow produces little or no blood cells.

The Whitakers, who now live in Oxford, had hoped their seven-month-old daughter Emily's umbilical cord blood could be used to replace Charlie's bone marrow, but the match wasn't good enough.

The desperate parents now say the only hope of curing Charlie of Diamond Blackfan anaemia is if they conceive a baby with matching stem cells.

Now the family hope the HFEA allow the stem cell transplant to be carried to before he is five-years-old, after which he will be too big for the process to work effectively.

Mrs Whitaker, 29, a radiologist who has lied in Bincester, Oxfordshire for six years, said: "There are only a limited number of cells and if Charlie is too big there won't be enough.

"After he reaches five Charlie would have to have a bone marrow transplant, but the chances of finding a suitable donor are very small and the best matches are siblings. "This means we only have an 18-month window so time is crucial."

The Whitakers are due to see one of Britain's top fertility experts at his private clinic in London who has agreed to carry out the treatment for free if they get permission.

Grandparents June and David Kynock, who still live in Chester-le-Street, have already raised £18,500 for research into the condition and plans other fundraising events later this year.