The pain of losing both her brother and uncle to muscular dystrophy is something Angela Jackson will never forget.

But thanks to incredible leaps in medical technology, she and husband Mark underwent a revolutionary testing process to ensure their child, now five, was disease-free.

As Angela had a 50 per cent chance of having an affected son she opted to use the screening process to ensure she had a female pregnancy that would be unaffected by the disorder.

An embryo, which turned out to be Katy, was tested to see whether it was male or female using a method like IVF called preimplantation genetic diagnosis (PGD).

It means Katy will never get the muscle-wasting disease, although she could be a carrier of the gene and would have to be tested before having her own children.

The treatment hit the headlines on Tuesday as it was featured in an episode of medical drama Holby City and the BBC documentary A Child Against All Odds.

The Jacksons - who live near Southmoor with Katy and other daughters, Samantha, 14, and Lucy, two - had the PGD treatment at Guy's and St Thomas's Hospital in London.

PGD involves taking one or two cells from the embryo and testing them either for the presence of a specific genetic disease like cystic fibrosis or sickle cell disease or to sex the embryo in X linked conditions, like haemophilia, that only affect boys.

A female unaffected embryo was then implanted into Mrs Jackson's womb.

Katy, who was born in Oxford, is one of 100 babies who were genetically tested at Guy's hospital using this method.

Alison Lashwood, consultant nurse in genetics and PGD, and part of the team who pioneered the new technology, said: "It is fantastic to have helped so many couples who were carrying genes for serious genetic disorders to have the babies they may have thought they could never have.

"We are very proud of this achievement and as one of the biggest and most advanced PGD centres in Europe, we hope we can help many more couples in the future."

Mrs Jackson, 42, who tragically lost both her brother Nigel Coombs and uncle Michael Dempster to Duchene's muscular dystrophy, said: "PGD has meant that we can have children and not be worried about them dying of a disease. It has enabled our family to eradicate muscular dystrophy from one generation.

"In our case, only one embryo was female OK, so we only had a 10 per cent chance of success."

The couple, who live in Kingston Hill, near Southmoor, had to pay for the treatment but it is also available on the NHS.

It is not legal in the UK to use the process simply to select the sex of a child for social reasons.

Preimplantation genetic diagnosis (PGD) was first introduced in 1990 as an experimental procedure.