Cancer Watch - UK baby to be born free of breast cancer
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01 July 2008
Inherited Gene ‘Screened Out’ From Woman’s Embryos To Eliminate The Disease From Couple’s Lineage
A woman has conceived Britain’s first baby guaranteed to be free from hereditary breast cancer.
Doctors screened out from the woman’s embryos an inherited gene that would have left the baby with a greater than 50% chance of developing the cancer.
The woman decided to have her embryos screened because her husband had tested positive for the gene and his sister, mother, grandmother and cousin have all had the cancer.
The couple produced 11 embryos, of which five were found to be free from the gene. Two of these were implanted in the woman’s womb and she is now 14 weeks pregnant.
By screening out embryos carrying the gene, called BRCA–1, the couple, from London, will eliminate the hereditary disease from their lineage.
About 5% of the 44,000 cases of breast cancer diagnosed in Britain each year are estimated to be caused by the BRCA–1 and BRCA–2 genes, both of which can be detected in embryos.
Doctors say thousands of cases of breast cancer could be avoided by screening embryos using the technique called pre–implantation diagnosis (PGD).
Many women who test positive for the gene have their breasts surgically removed to avoid the disease. Only one other woman – an Israeli motherto–be – is thought to have become pregnant after undergoing the embryo screening.
The 27–year–old British mother, who asked not to be named, says that after seeing all her husband’s female relatives suffer from breast cancer, she felt she had to take action to save their children from the same plight. Any daughter born with the gene would have had a 50% to 85% chance of developing breast cancer.
She said: “For the past three generations, every single woman in my husband’s family has had breast cancer, as early as 27 and 29. We felt that, if there was a possibility of eliminating this for our children, then that was a route we had to go down.”
Tests on the 11 embryos were conducted by removing just one cell when they were three days old. Six of the embryos carried the breast cancer gene. Two embryos that were free of the gene were then implanted, resulting in a single pregnancy.
The couple have also been able to freeze two healthy embryos for future use.