21 February 2011
ByAppeared in BioNews 596
Mutants and What to Do About Them
Conway Hall, Red Lion Square, London WC1R 4RL, UK
Wednesday 9 February 2011
'There's a bar at a nightclub and a girl is deciding whether to take some guy she's met home with her. She's not intent on asking does he dance well or does he have a good sense of humour… no, no, no. She takes a little bit of his hair and she runs out the door, down the street to the local genome shop… she hands over the hair with her credit card and comes back in 15 minutes. She opens up the envelope and she says, 'Wow, he's got a genetic quotient of 99'. She goes back to the bar and says - in so many words - 'Get your coat mate, you're pulled''.
This scene from 'Battlestar Galactica' introduces Professor Armand Marie Leroi's vision for the future. In ten years, we will have our genomes on our laptops; not for our own use, but for the sake of the next generation. The blending of a couple's biological dowries on a screen will predict the genetic soup of good and bad mutations inherited by future children.
This is the annual Darwin Day Lecture, chaired by Professor Richard Dawkins at the Conway Hall, London. Professor Leroi is an evolutionary developmental biologist at Imperial College and famed in the public eye for his book 'Mutants' (2003), where he takes the reader on a historical and biological journey of how genes and their mutations affect the way we look, think and feel and how they cause disease.
In the closing chapter, he argues scientists don't need to 'predict the future course of humanity or to moralise about it'. So I received his opening words with surprise: 'Tonight, I am going to speak about the future. The reason I am going to do this is because, frankly, I think the future is here'. He was arguing the vast advances in genetic technologies that have erupted in the past decade mean the bar scene in Galactica may not be science fiction after all.
Professor Leroi envisaged using these technologies to screen out bad mutations from our gene pool; recessive mutations, in particular, which only have an effect when we have two copies of them and which we're unaware of carrying. So far, 34575 recessive mutations have been identified. Cystic fibrosis is a well-known example where we can carry the mutation without having the disease but, if our partners also carry the mutation, we can pass this on to our children. On average, the chance of having children with someone who carries the same mutant gene as you is one in 107. The chance of the children inheriting both copies of the mutant gene is one in 428.
So what do we do about mutants? Professor Leroi's answer was simple. He proposed eventually women would undergo IVF treatment and have their embryos screened, eliminating those carrying mutations associated with adverse consequences. To validate his prediction, he dealt with all the reasons why this wouldn't happen. For example, it is ethically unacceptable and it would cost too much.
On the question of ethical acceptability, he said this form of eugenics already exists. In England and Wales, 92 percent of pregnant women presented with a diagnosis of Down's Syndrome opt for a termination of the child's life. He concluded that the public would not reject his notion on ethical grounds.
To the argument of cost, he reported that there are currently 51,000 cases of congenital mental retardation in the US and that the lifetime surplus medical costs of each child are US$1m, which amounts to a total cost of US$51 billion. The costs of IVF treatment and genome sequencing would be offset by medical cost savings.
But I wondered how he defines a bad mutation or, more precisely, whose life is not worth living? For I see a smiling child with Down's Syndrome, look at the masses of miserable faces, and wonder how we can make this distinction? Even if we could, our biggest genetic burdens often result from the combined effects of many genes and no amount of screening will ever rid us of these. We could eliminate an embryo carrying a copy of a cystic fibrosis gene and then select one whose genes predispose the child to autism instead.
Professor Leroi told a simple-sounding story when we know so little about the genetic origins of disease, how different genes interact with other and how superficial modifications in our DNA affect their function. I doubt we could ever confidently assign genetic superiority to one embryo over another and what message would this send to society if we could? With choice comes dissatisfaction and regret.
Professor Leroi also failed to mention the long-term unknown effects of IVF on future generations. It will be 50 to 100 years or more before we see any potential problems and until then, we cannot consider putting all our eggs in one basket.
I noticed an inscription on the gables of Conway Hall: 'To thine own self be true'. With irony, the words hung above an enraptured audience being sold a prophecy which frames modern science as superior to the forces of nature. More ironically, this lecture was commemorating Darwin's birthday. At the very heart of Charles Darwin's theory of evolution is mutation and 10 years' experience with DNA versus millions of years of evolution doesn't smack of sensibility.
This aside, it seems hypocritical for us to begin quality checking genetic passports before allowing access to this world. After all, most misery and disease finds a root in our own society, not our DNA. Yet the audience grunted in awe at Professor Leroi's revelations and he was wildly applauded, except by the two aghast scientists sitting in the gallery.
It was when the gentleman sitting beside me cried the word 'Superb!' that I was shifted from my seat by some force: moral compulsion, a responsibility to science, I'm not sure. We joined the queue of question-eers. Questions were largely emotive. One man spoke of his hope that his daughter could screen out embryos so that her children wouldn't suffer from Type-one diabetes. Yet Professor Leroi failed to mention this would be impossible because multiple genes and environment-gene interactions are likely to result in this condition.
The words 'Hitler' and 'Nazi' were muttered several times. In response to a worry that far- right and left-wing governments would deploy this technology to extreme levels, Professor Leroi again avoided the question. He said with laughter, 'eugenics would be the least of worries'.
Perhaps Professor Richard Dawkins saw a glint of challenge in our eyes when he ended the questions preceding our turn. But it wasn't us who were let-down, it was all those in the audience who didn't have the scientific background to see the fundamental flaws and critical omissions in Professor Leroi's arguments. An enthralling lecture and an engaging speaker, but they were deceived victims of media-trophic science and an appetite for fame.
It was with some amusement on my return home that I spied a man squirming uncomfortably next to an oversized teddy bear holding a fluffy heart reading, 'I love you'. I wondered how all children would be born by IVF because I think nature would win on willpower…