Genetic testing and the corruption of science

Pre-implantation genetic testing or screening IVF embryos for signs of crippling disabilities, to use its sexier title, has been back in the papers again over the last few weeks. In little more than a year, the BBC tells us, a universal gene test, karyomapping, which can detect almost any inherited disease in a newly formed embryo, will go on sale to the masses for a paltry £2,500. Of course that is still dependent on the Bridge Centre Clinic, the developers of the technique, being granted a license to practice by the Human Fertilisation and Embryonic Authority, but then the public pressure generated from ‘good news’ stories like this should help to speed the process along nicely.

Naturally, the press has responded to the news with their trademark ‘slippery slope’ journalism bringing out all their greatest hits from previous debates including: designer babies, the annihilation of the disabled community etc. While genetic testing does carry very serious ethical implications, it always bothers me how we seem unable to debate it without resorting to such hysterics. However, what really bothers me is that nobody seems to have paid much attention to the most important question – does it even work?

The original aim of the technology, when it was first developed back in the 1980s by UK Professor Alan Handyside, was to improve the success rate of IVF by screening the chromosome counts of each newly created embryo before implanting it into the mother to be. An abnormal number of chromosomes automatically results in miscarriage –with the exception of Down’s Syndrome- so by ensuring only embryos with the right number of chromosomes were implanted, doctors hoped, the number of IVF babies successfully carried to term would dramatically increase.

However, a 2004 feature on the technique by New Scientist magazine revealed several problems. First, clinics in the U.S offering genetic tests to IVF patients did not have to report their findings to the government, so there was no impartial oversight of their effectiveness. Second, barely any clinical trials of the technology had been conducted, the most comprehensive one involving just 55 people, nowhere near enough to produce reliable results. Third, and most important, according to Professor Handyside himself, the accuracy of the tests was so questionable that as many as 1 in 10 of embryos discarded as ‘defective’ could actually have developed into healthy newborn babies. What’s more there was no evidence that the test helped more women to conceive using IVF than before.

What was wrong with the tests – aside from the absence of peer review and government oversight? Each screening, the results of which would determine whether to proceed with the IVF treatment in which countless parents had invested their savings, was carried out on just a single embryonic cell. This was problematic due to the fact that it is entirely possible for the extracted cell to possess abnormal numbers of chromosomes, or traces of any number of disabilities for that matter, while the embryo itself remains completely normal. Similarly, the reverse proved equally possible with at least one reported case of a baby being born with Down’s Syndrome after a genetic test failed to detect any problems with the original embryo.

So, what’s changed since then? The range of conditions detected by karyomapping has increased exponentially and the time taken to perform it substantially reduced. As a result, the number of IVF patients turning to genetic testing, and the number of embryos aborted, is likely to sky-rocket too. However the technique itself of testing a single cell for all these conditions remains exactly the same. As for independent oversight, the PHG Foundation, devoted to exploring the application of scientific research to healthcare complained last October that: “there have been no scientific publications describing the details of the new methodology, and no clear explanation of how exactly multiple genetic traits are identified.” To date, no clinical trials have been completed either. Preliminary tests boast a success rate of 100%, but that becomes less impressive upon realising they were carried out on just five embryos.

So, what does Professor Handyside have to say about the technique now? In an interview with the Times on July 1st, he was surprisingly on message, saying: “This is a truly universal test for genetic defects in embryos.” Is this because sometime after that previous interview in 2004, he had an epiphany and a sudden change of heart? Or could it be that as the Director of the Bridge Centre Clinic responsible for pioneering this universal test, he now stands to cash in on the fears and desperation of the IVF patients unable to conceive naturally? But then why let good science stand in the way of such a prime business opportunity?