Embryo bowel cancer test approved
Dr. Kirsty Horsey
Progress Educational Trust
01 November 2004
The UK's Human Fertilisation and Embryology Authority (HFEA) has issued a licence allowing doctors to test embryos for a gene mutation that confers a high risk of bowel cancer. Four couples at risk of passing on familial adenomatous polyposis coli (FAP) to their children are now set to undergo the treatment at the Assisted Conception Unit at University College Hospital (UCH) in London.
FAP is a rare genetic condition, characterised by the presence of hundreds of pre-cancerous 'polyps' in the bowel. Although each individual polyp has a fairly low risk of becoming cancerous, the patient has so many polyps that colon cancer is almost inevitable by the age of 50, and usually develops between the age of 20-40. Currently, the only way to prevent the disease is by surgically removing the colon. Any child born to someone affected by FAP has a fifty per cent chance of inheriting the condition.
Paul Serhal and his team at UCH will test embryos created using in vitro fertilisation (IVF), and only transfer into the womb those that are free of the FAP gene mutation. 'This will be able to wipe out a defective gene completely, allowing couples to have children without the fear that they may be passing on a terrible illness', Serhal told the Times. One of the patients who will benefit from using PGD to test for FAP is a 35 year-old man from Bristol, who was diagnosed with the disease at the age of 19. He had to have most of his colon removed, and now undergoes an annual invasive screening test to check for the presence of polyps. He told the newspaper that his wife 'already has the stress of worrying about me', adding 'to add that for our children would be a great burden'.
The licence is the first to be granted to allow UK couples to use PGD to test for a 'late-onset' condition which, although it confers a very high risk of disease, might never cause cancer. However, this approach has been used elsewhere to eliminate the risk of cancer - in 2001, doctors at the Reproductive Genetics Institute in Chicago used PGD to ensure that a couple conceived a baby free from the inherited cancer condition Li-Fraumeni syndrome. In June 2004, UK IVF doctor Mohammed Taranissi announced that he would be applying for a licence to use PGD to tests embryos for gene mutations that cause familial breast cancer. At the time, he called for a public debate, and a national policy on the use of PGD for late-onset conditions, so that clinics would not need to seek permission on a case-by-case basis.
The HFEA's decision has attracted criticism from pro-life group Comment on Reproductive Ethics (CORE): 'The HFEA has yet again taken a big ethical decision without consulting the public', said director Josephine Quintavalle. She said that FAP was a 'clear example' of a disease that people can do something about, and asked 'how will doctors learn to cure cancer if they kill the genes instead of trying to treat them?' But Alistair Kent, director of the Genetic Interest Group, said that both breast cancer and FAP 'carry a very high risk of cancer, which requires a big, invasive operation to reduce, and cannot be eliminated completely'. He welcomed the HFEA's decision to licence PGD for FAP, calling it a 'human and sensible use of technology for people who find themselves carrying unpleasant genetic diseases'.
© Copyright Progress Educational Trust
Reproduced with permission from BioNews, an email and online sources of news, information and comment on assisted reproduction and genetics.
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