This article appears in the August 1998 edition of the Catholic Medical Quarterly
Return to August 1998 CMQ
PREIMPLANTATION DIAGNOSIS
Conference organised by Centre for
Bioethics & Public Policy
Royal Society, 6 Carlton House Terrace,
London SWI 5AG: 6 May 1998
It was a great honour in itself to view the home of the Royal Society, magnificently situated on Carlton House Terrace. One was transported back to the 17th century by the studded ceilings and the paintings of almost every scientist one had ever heard of.
Lord McColl chaired the morning session which was dominated by the clinical issues presented by Lord Winston. In his view, preimplantation diagnosis is not a means of supplanting God nor indeed playing God. It is rather a means of promoting and preserving human life and influencing reproduction in a proper manner. Presumably he accepts that something has failed, and it is the duty of the scientist to remedy it. He admits that it has a limited value for a small number of patients and in itself will not reduce genetic diseases. Even with a perfect screening programme, one could only minimally reduce genetic diseases, as many of the severe forms are mutations. At the Hammersmith Hospital, the first to offer this form of diagnosis in the UK, perhaps 200 hundred babies have been born after being subjected to the method. But, as one speaker pointed out, this figure ignored the fact that several hundred thousand embryos have been created and stored away with an uncertain future.
David King, editor of GenEthic News, feels we are now in a state of laisser-faire eugenics, due to the current regime of pre-natal testing and 'non-directive' counselling. Sex is for fun, but having a baby is a serious matter. In ten years time preimplantation diagnosis ( PID) will be widely available. As it deals with an embryo, the option of continuing with an affected pregnancy will be abolished. Such an action would not be an abortion as the affected embryo is not implanted. And, although its use is at present limited by the problems of IVF, he would argue that this is likely to change in the future. Furthermore, he feels that the ease of selection and the multiplicity of embryos will make the slippery slope, between serious impairments and non pathological characteristics, much more slippery. It is likely to encourage the existing culture of medical surveillance of reproduction and quality control of embryos: a situation which, he finds, offends our dignity as human beings and will require extremely strict regulation.
The accuracy of genetic tests on one or two cells was questioned by Dr. Pete Moore. Since single disease may have many variations, the certainty of a correct prediction must be doubtful. As the only treatment available at present is the disposal of the embryo, the safety of the procedure requires full evaluation: that may take a lifetime. Furthermore fully informed consent to the procedure must be obtained.
Although the genetic diseases regarded as suitable for embryo disposal are frequently highlighted, Michael Jarmulowicz examined some of them more closely. The main case for PID is to influence sex linked disorders. But polyposis coli and carcinoma of the breast, regarded by Professor Winston as eminently suitable, have other forms of treatment. The incidence of the former can be detected at an early stage and eradicated by judicious colectomy. Other points he raised included the finding that only 10% of possible inheritors of Huntingdon's Disease take up the test. From the floor, the point was raised that, although it costs £80,000 to identify a baby with Down's Syndrome, the cost of bringing it up is approximately £120,000.