A baby genetically selected to be free of breast cancer has been born in a London hospital. The baby girl is doing well.
The mother-to-be, a 27-year-old Londoner, opted for screening after three generations of her husband's family developed an inherited form of breast cancer in their 20s.
Her 28-year-old husband is a carrier and those diagnosed with the disease include his mother, sister, grandmother and cousin.
She said: 'We had been through his sister being ill, so it was something we had seen first hand.
'I thought this was something I had to try because, if we had a daughter with this gene, and she was ill, I couldn't look her in the face and say I didn't try.'
Without screening, any girl the couple had would have had a high chance of developing a fast-spreading, hard-to-treat form of breast cancer.
Doctors at the University College Hospital created embryos through IVF then screened them for the deadly gene before transferring only healthy ones into the womb.
The pioneering treatment was carried out on the NHS.
Paul Serhal, medical director of the hospital's assisted conception unit, said today: 'This little girl will not face the spectre of developing this genetic form of breast cancer or ovarian cancer in her adult life.
'The parents will have been spared the risk of inflicting this disease on their daughter.
The lasting legacy is the eradication of the transmission of this form of cancer that has blighted these families for generations.'
Had the couple conceived naturally, any child would have a 50 per cent chance of carrying the rogue gene.
And any girl with the BRCA1 gene would have an 80 per cent chance of developing a fast-spreading, hard-to-treat form of breast cancer.
The gene also gives a woman a 60 per cent chance of ovarian cancer and raises a man's risk of prostate cancer.
To screen it out, doctors used IVF techniques to create a selection of embryos. When they were three days old, one cell was plucked from each and analysed for the rogue gene.
Two of the five embryos found to be free of the gene were transferred into the woman, of which one resulted in to the pregnancy.
Many more couples could benefit from pre-implantation genetic diagnosis, or PGD.
Mr Serhal, who has already created babies free from inherited eye and bowel cancers, said: 'A patient doesn't enter into this procedure lightly. They had genetic counselling and a lot of soul searching before going into this treatment.'
Until recently, PGD was used only for genes which invariably cause incurable diseases when inherited - such as those behind cystic fibrosis.
Two years ago, the Government's fertility watchdog, the Human Fertilisation and Embryology Authority, relaxed the rules.
Doctors can now screen for genes which, while raising the risk of illness, do not always lead to the condition.
They can also look for embryos free of flaws which cause disease late in life, including a rare inherited form of Alzheimer's.
Addressing concerns that this is another step towards the creation of babies made to order by characteristics such as eye colour or hair colour, Mr Serhal said: 'This is a serious disease, not a physical characteristic. We are not screening for something banal or irrelevant.'
But pro-life campaigners claim it is morally wrong to weed out imperfect babies and describe the technique, in which unhealthy embryos are left to perish, as a 'tool for search and kill.'