UK clinic allowed to screen embryos for rare bowel cancer
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《英国医生杂志》
Doctors in London have been given the go-ahead to screen embryos for a rare inherited form of bowel cancer after pressure from families affected by the condition.
The assisted conception unit at University College Hospital is the United Kingdom's first clinic to be granted a licence to perform pre-implantation genetic diagnosis (PGD) to select embryos that are free of the genetic mutation that leads to familial adenomatous polyposis (FAP).
Four couples affected by the condition, and who have a 50% chance of passing the mutated gene to a child, will start treatment for the procedure at the end of the year. Until now, the only reproductive option for families carrying the FAP gene has been for the fetus to be tested for the condition during pregnancy, with the option of termination if it is found to have inherited the condition.
Familial adenomatous polyposis affects between 1 in 26 000 and 1 in 44 000 people in the United Kingdom. It leads to multiple rectal and colon cancers in early adulthood for almost all of those affected by the condition. Most opt to have prophylactic surgery to remove the colon, usually in their teens.
The new licence is the first time that doctors in the United Kingdom have been allowed to test for a genetic disorder that affects adults and which can be treated. Until now, clinics have been allowed only to screen embryos for untreatable conditions or conditions that affect children, such as Huntington's disease and cystic fibrosis.
The decision to grant the licence could have far reaching consequences, say observers. It could lead to fertility clinics being allowed to screen for other genes that increase the risk of cancer, such as the breast cancer genes BRCA1 and BRCA2. However, inheriting mutations in these genes does not guarantee that cancer will develop.
Dr Ros Eeles, reader in clinical cancer genetics at the Institute of Cancer Research, said that screening for FAP was less controversial than for other cancers. "Everyone who inherits the FAP gene will get cancer and even if the bowel is removed there is a risk that they will get cancer in the upper gastrointestinal tract," she said. But granting of the new licence has been condemned by the pressure group GeneWatch UK, which monitors developments in genetic technologies.(Zosia Kmietowicz)
The assisted conception unit at University College Hospital is the United Kingdom's first clinic to be granted a licence to perform pre-implantation genetic diagnosis (PGD) to select embryos that are free of the genetic mutation that leads to familial adenomatous polyposis (FAP).
Four couples affected by the condition, and who have a 50% chance of passing the mutated gene to a child, will start treatment for the procedure at the end of the year. Until now, the only reproductive option for families carrying the FAP gene has been for the fetus to be tested for the condition during pregnancy, with the option of termination if it is found to have inherited the condition.
Familial adenomatous polyposis affects between 1 in 26 000 and 1 in 44 000 people in the United Kingdom. It leads to multiple rectal and colon cancers in early adulthood for almost all of those affected by the condition. Most opt to have prophylactic surgery to remove the colon, usually in their teens.
The new licence is the first time that doctors in the United Kingdom have been allowed to test for a genetic disorder that affects adults and which can be treated. Until now, clinics have been allowed only to screen embryos for untreatable conditions or conditions that affect children, such as Huntington's disease and cystic fibrosis.
The decision to grant the licence could have far reaching consequences, say observers. It could lead to fertility clinics being allowed to screen for other genes that increase the risk of cancer, such as the breast cancer genes BRCA1 and BRCA2. However, inheriting mutations in these genes does not guarantee that cancer will develop.
Dr Ros Eeles, reader in clinical cancer genetics at the Institute of Cancer Research, said that screening for FAP was less controversial than for other cancers. "Everyone who inherits the FAP gene will get cancer and even if the bowel is removed there is a risk that they will get cancer in the upper gastrointestinal tract," she said. But granting of the new licence has been condemned by the pressure group GeneWatch UK, which monitors developments in genetic technologies.(Zosia Kmietowicz)