Screening human embryos for a rare genetic condition leading to bowel cancer in order to select embryos lacking the pre-disposition has been given the go-ahead in the UK.
The UK鈥檚 Human Fertilisation and Embryology Authority (HFEA) has granted a licence to doctors to screen embryos for the gene that causes familial adenomatous polyposis coli, or FAP. This will enable couples carrying a gene for the disorder to select embryos for implantation that are not predisposed to the condition.
The HFEA confirmed it had granted the licence for pre-implantation genetic diagnosis (PGD) for FAP to the Assisted Conception Unit at University College London on Monday.
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鈥淔AP is a serious condition 鈥� prenatal diagnosis and selective termination of affected cases has been offered in the past,鈥� it said in a statement. 鈥淔amilies with the genetic condition have a 50% chance of passing it on to their children, but using PGD can help these families have a healthy child.鈥�
Mind shift
FAP is a severe colon condition which is inherited through a single dominant gene. Initially, it causes benign swellings, called polyps, in the colon. But there is a high risk that these will go on to cause bowel cancer in the sufferer鈥檚 twenties or thirties.
Paul Serhal, medical director at the Assisted Conception Unit, says that the HFEA has made a landmark decision. 鈥淚t鈥檚 a shift in thinking, from trying to treat cancer to preventing cancer.鈥�
However, some pro-life groups are unhappy with this. 鈥淲e are not thinking about curing the disease, but about eliminating the carrier,鈥� says Josephine Quintevalle, of the group Comment on Reproductive Ethics.
The HFEA says the licence was granted because of the high risk of passing on FAP. 鈥淚t鈥檚 been issued in this instance because it鈥檚 very likely that a person carrying it may pass it on to their child,鈥� Lara Gorman, a spokeswoman for the HFEA, told New 杏吧原创.
She says that any such future licence application for using PGD to select out other cancers would be considered 鈥渙n a case-by-case basis鈥� for a range of factors, including the likelihood of the disease being passed on or developing, the degree of suffering associated with the condition and the availability of therapies 鈥� either now or in the future.
Embryo wastage
Serhal rejects criticism of the licence. 鈥淚t鈥檚 not dabbling with nature 鈥� it鈥檚 giving a helping hand to nature. Selection does happen in nature, there鈥檚 lots of embryo wastage normally,鈥� he told New 杏吧原创. 鈥淲e are not screening for physical characteristics. This is a sensible approach to preventing cancer.鈥�
He also emphasises that 鈥渋f a child has FAP, they will develop cancer 鈥� there鈥檚 no question of that鈥�. The HFEA is almost as categorical: 鈥淔AP leads to multiple rectal and colon cancers in early adulthood for almost all of those affected by the condition.鈥�
Serhal is now carrying out preliminary work on the possibility of using PGD to identify embryos predisposed to breast cancer and retinoblastoma.
Women carrying the genes BRCA1 and BRCA2 are up to 80% more likely to develop breast cancer than those without these gene forms. And retinoblastoma 鈥� an eye cancer 鈥� is caused by a single inherited gene, he says.