New Technique To Cull
Embryos At High Cancer Risk
BBC News

British scientists are developing a technique to weed out embryos at high risk of developing cancer.
The technique involves the genetic screening of embryos before they are implanted in the womb using in vitro fertilisation (IVF) techniques.
The development is to be evaluated by the Human Fertilisation and Embryology Authority, but moves to weed out "unacceptable" embryos have been described as the "Nazification" of medicine by a leading expert on medical ethics.
Joy Delhanty, professor of Human Genetics at University College Medical School, is among those working on the new technique, which has been successfully tested on one family with a high risk of producing children susceptible to colon cancer. It is now being perfected to test for other types of the disease.
Professor Delhanty said: "We are dealing with families where there is a very high risk of cancer due to the inheritance of a faulty gene.
"This means that if the parent has this gene then each child has got a one in two chance of inheriting that gene and therefore developing the cancer during their lifetime.
"What we are aiming to do is to give these parents the option of starting a pregnancy knowing it will not have that faulty gene."
The technique involves testing one or two cells from a three-day-old embryo before it is implanted in a mother's womb.
The embryo is then only implanted if the tests show that the it is not carrying the faulty gene.
Scientists originally developed the technique at the beginning of the 1990s to test for a risk of cystic fibrosis.
Professor Delhanty said: "In principle it could be applied to any condition where the genetic basis is well understood, and where it is simple."
Ethical difficulties
Dr Richard Nicholson, editor of the Bulletin of Medical Ethics, warned that the technique was fraught with ethical difficulties.
He said: "We are now moving rapidly into an age of are saying there are lives that are not worth living, and we either prevent them by abortion if they are discovered ante-natally, or we now are moving into the hi-tech way of pre-conceptional prevention.
"People hate to talk about Nazification of medicine, but this is actually what is happening. It took only 25 years in Germany to go from individual doctors saying there are certain lives not worth living, to having mass euthanasia programmes.
"We have got to look very carefully to the way we are gradually progressing to preventing people with disease, rather than preventing diseases."
Ruth Deech, chair of the Human Fertilisation and Embryology Authority, said the authority was working on new guidelines for screening techniques, and would hold a public consultation exercise later in the year.
She said: " We are only too well aware of the sort of dangers that have been described, which is why we inch forward very carefully indeed with counselling for parents."