This week she went to Brussels to lobby Members of the European Parliament who are due to vote on the issue next Monday. She is campaigning for an amendment that would exempt diagnostic tests, and hopes that this will be debated next week. She has already enlisted the support of fellow carriers of the gene and has encouraged some of Britain's leading genetic scientists to add their voices to the protest.
"We can't allow it to happen," she says. "If we did, companies would just be able to stick a flag on any old gene they find and anyone who wanted to use it would have to pay them. If, eventually, they find 15 genes for breast cancer, as is expected, women may have to pay for 15 different tests. It is a scandal that must not be allowed to happen."
When she is not firing off letters to MEPs, MPs, ministers and other potential supporters, or running a helpline for fellow sufferers of inherited breast cancer, Wendy Watson, 42, runs a farm in the Peak District with her policeman husband, Chris. She is no stranger to campaigning and taking hard decisions about genetics. This is an issue that has dogged her life since childhood, when she watched her mother die of breast cancer.
"I was only 16, but I knew something was wrong," she says. "My mum had died and her mother had twice had breast cancer, but I had a job trying to convince anyone that it was inherited. I wanted to know if I was at risk and if it could be passed on, but in those days no one had the answers.
"Over the next 20 years I worried about it, but all the doctors took the attitude of, `Don't be silly; stop worrying; pull yourself together.'"
When she and her husband moved to their Derbyshire farm, in an area where her mother's relatives lived, she soon discovered that there were far more than two cases of breast cancer in the family.
"I found that my mum's second cousin had had it twice, her sister had died, and her mother, and an aunt, and a cousin had both got it. Eventually I found nine cases of breast cancer in the family, and that did not include the male relatives who also carried the gene and could pass it on to their children.
"I drew up a family tree and took it to the GP, but the only thing he could offer was a three-monthly check-up and early mammography. There was a drug trial, too, but even if I could have got on it, there was the risk that I would get the placebo rather than the drug, and that would have been useless for me.
"I came back home and started to read up all I could on cancer, and asked a lot of questions. Then it suddenly dawned on me one day how ridiculous it all was. Here I was waiting to get the cancer, after which I would have a mastectomy. Why not have a mastectomy now to prevent ever having the cancer? I thought it was a very clever idea and I couldn't think of one argument against it. At that time I don't think it had been done here in the UK before but I went to my doctor, who sent me to a specialist, then a family history clinic and then a geneticist. When I met the geneticist it was breath of fresh air to talk with someone who agreed with me and thought I was being sensible.
"To me it was perfectly clear. I was worried about dying, not about surgery or losing my breasts. People ask me, for some reason, what my husband thought about having a double mastectomy, and I tell them how supportive he was. Some women worry about that side of it, but I tell them that I wouldn't think much of a man who was more concerned about saving my breasts than my life."
Five years after her operation, the gene BRCA1 on chromosome 17, which predisposes women to breast cancer, was found after a long search by teams of scientists around the world.
It is now estimated that 2 per cent of breast cancers and 3 per cent of ovarian cancers are due to BRCA1, but among women under 30 it may be responsible for as many as 8 per cent of breast cancers. Those who carry the mutation have a 50 per cent chance of passing it on to each of their children. They also have an 85 per cent of developing ovarian cancer.
"It was a very big breakthrough for women around the world. It meant that a simple test could be designed so that women could find out whether they had the gene, without a long family tissue search which in many cases was not possible, because relatives were dead."
The first hint of controversy came when Utah-based Myriad Genetics, which located BRCA1 and which offers a breast cancer test in the US for about pounds 1,200, applied for a UK and European patent for the process.
So far it has not been given, but a new draft directive, due to go before MEPs next week, would pave the way for widespread genetic patenting like this and make it much more common in future.
The crucial passage in the directive says: "The subject of an invention capable of industrial application which relates to an element isolated from the human body or otherwise produced by means of a technical process shall be patentable, even if the structure of that element is identical to the natural element."
According to Wendy Watson, and to scientists and a coalition of European pressure groups, this would make it possible for the first time in Europe to patent parts of the body.
Bio-tech companies reject protests about the prospect of patenting and say that without the protection of a patent no one would be able to afford the research. Bill Hockett, the director of corporate affairs for Myriad, says: "We found the gene, and our application relates to the full sequence of the gene and other aspects of using the gene for commercial purposes. The gene would probably not have been discovered yet but for the potential of patenting. Without the protection that the patent affords, a company could not invest hundreds of millions of dollars in getting it to the market-place. If anyone could use the results of our research and our investment, it would not be worth much for people who invested in our company."
Dr Gareth Evans, a geneticist, and a number of colleagues have written to MEPs to protest: "The isolation of genes has come in most instances from world-wide collaboration and with the help of many institutions including charities and the Medical Research Council. Allowing the successful company to plant its flag on a particular gene is a new form of colonisation and is not a fair reflection of the work involved in identifying the gene."
There are fears that the breast cancer gene application is likely to be just the beginning. With the imminent completion of the Human Genome Project, gene-based therapies for hundreds of diseases are just around the corner.
For many people, patenting gene-based data like this will not be an abstract debate about ethics and morals, but a very real problem that may well mean the difference between life and death. The real danger for them is that if universal patenting of genetic material is allowed it may well make the cost of genetic testing prohibitively expensive. The result could be that the NHS would simply not be able to pay the price for its patientsn
Hereditary Breast Cancer Helpline: 01629 813000Reuse content