Imagine, for a moment, that you have a headache. You take a paracetamol. What happens next? In most cases, the headache goes away; or at least gets a little better. Very rarely, though, paracetamol causes an allergic reaction. And in a tiny proportion of those cases, that reaction proves fatal.
It’s one stark example of a set of questions with profound significance for medical science and, by extension, for all of us. Why do some people suffer extreme allergic reactions to medicines at all? Indeed, why do some people become ill – with Alzheimer’s, diabetes, heart disease, lung cancer – while others don’t? Why do some people have trouble sleeping and others staying awake? And, crucially, how can we tell who will be afflicted by which problems, in time to do something about it?
Of course, one’s lifestyle and environment provide parts of the answer to these sorts of questions, but only partly. Now, we’re on the verge of a revolution that will allow us, say proponents, to complete the jigsaw puzzle. It’s being called personal genetics: it’s certain to transform medicine, and it could change the way we live our lives, too.
At the forefront of all this is the world’s first personal genetics company, 23andMe (www.23andme.com), which this month applied to the US Food and Drug Administration for approval for its personal DNA tests.
For US$299 (Dh1,097), 23andMe will send you a sample cup. Spit into it and put it in the post, and they’ll test for more than 900,000 different DNA sequence variations and send you the results. That means potentially life-changing insights into your risk for major diseases such as breast cancer and Alzheimer’s, and your likely response to a range of medicines, such as selective serotonin reuptake inhibitor antidepressants. There’s also a chance to map your ancestry and uncover hidden potential: do you have genes for the fast-twitch muscle fibres associated with sprinting ability, or the SNAP-25 gene associated with high non-verbal intelligence?
Now, more than 150,000 people have used 23andMe – the company is named after the 23 pairs of chromosomes in a human cell – to analyse their DNA. Some have discovered a propensity for fatal diseases, just in time. Others have found siblings, or parents who gave them up for adoption. Indeed, 23andMe tests uncovered the surely never-guessed-at fact that the lifestyle guru Martha Stewart is related to the actor Samuel L Jackson.
Proponents of personalised genetics say we can look forward to a world in which our DNA becomes another key personal metric, like our shoe size. That means medicines devised and prescribed according to a genetic analysis of how we’ll respond, and lifestyle and diet advice tailored to our genetic make-up. And what of the more distant future? Will our grandchildren choose careers and life partners based partly on genetic insight into their aptitudes, and compatibility?
We’ll soon find out, thanks in large part to the key driver here: cost. It took 10 years and $3 billion for the Human Genome Project to sequence the first full human genome, released in 2003. In 2007, the DNA scientist James Watson had his genome sequenced in months, for $2 million. Today, a whole genome can be sequenced in 24 hours, for just over $1,000. Personal genetics is about to go mainstream – and the world will never be the same again.
David Mattin is a senior analyst at www.trendwatching.com
