Genetic data will soon be accessible like never before. The implications for our health are huge
While at the till in a clothes shop, Ruby received a call. She recognised the woman’s voice as the genetic counsellor she had recently seen, and asked if she could try again in five minutes. Ruby paid for her clothes, went to her car, and waited alone. Something about the counsellor’s voice gave away what was coming.
The woman called back and said Ruby’s genetic test results had come in. She did indeed carry the mutation they had been looking for. Ruby had inherited a faulty gene from her father, the one that had caused his death aged 36 from a connective tissue disorder that affected his heart. It didn’t seem the right situation in which to receive such news but, then again, how else could it happen? The phone call lasted just a few minutes. The counsellor asked if Ruby had any questions, but she couldn’t think of anything. She rang off, called her husband and cried. The main thing she was upset about was the thought of her children being at risk.
Over the next few weeks, she Googled, read journal articles, and tried to become an expert patient in what was quite a rare genetic disorder. There wasn’t much to go on, and, not being a scientist herself, it was hard for her to evaluate what she did find. She learned that a link between mutations in this particular gene and connective tissue problems had only recently been discovered. A few years earlier this disease did not exist, or at least it had yet to be named.
Over time, some details emerged. Nobody had ever seen her own family’s particular mutation in anyone else. So that meant it was very hard to know what to make of her situation. Her risk of a heart problem was surely increased, but nobody could say by how much.
Every one of us will be shown to be subtly suboptimal – or every one will be shown to be special
From that initial phone call, it was six months before Ruby was seen by any other medical professional. She saw a cardiologist first, followed by a series of other specialists, since each appointment seemed to trigger a chain of others. The outcome was that Ruby would have regular body scans, and she began to take medication to lower her blood pressure, which she was told to do as a precaution for the rest of her life. She was also told to avoid anything that would cause her body to suddenly jolt. The vagueness of what this meant in practice became another source of worry. Should she carry on playing basketball, for example? She had always loved going abroad, but now travel insurance became exceptionally hard for her to get, partly because nobody knew how to categorise her.
Ruby believes that it was definitely better to have been informed of her genetic inheritance, because in her case there were things she could do to lower the risk of it becoming a real problem. But it took a long time for her to understand that she was not actually ill. She was only at risk of being ill. In fact, nothing had actually changed; she had only become aware of a possible future.
Every one of us is susceptible to one illness or another to some extent. As science progresses, many more of us will find ourselves in Ruby’s situation; drowning in estimates and probabilities that play games with our mind and our identity, and require us to make difficult decisions about our health and how we live. Every one of us will be shown to be subtly suboptimal. Or every one of us will be shown to be special. It depends on how you look at it. As Andrew Solomon writes in Far from the Tree: “The general culture feels that deaf children are primarily children who lack something: they lack hearing. The Deaf culture feels that they have something … membership in a beautiful culture.”
We must be very careful in defining what constitutes disease or disability, especially as our ability to link genes with human traits expands. Bill Bryson puts it like this in The Body: A Guide for Occupants: “Twenty years ago about 5,000 genetic diseases were known. Today it is 7,000. The number of genetic diseases is constant. What has changed is our ability to identify them.”
Even in the hard data, things get messy. For example, someone who has inherited an immune system gene called HLAB27 is about 300 times more likely to develop the autoimmune disease ankylosing spondylitis. Around 8% of people in the UK have this gene variant and most do not suffer from the disease. What’s more, inheritance of this gene may be useful in fighting HIV. About one in 300 people infected with HIV are able to control the virus so that they don’t go on to develop Aids, at least for a very long time, and HLAB27 occurs frequently in these people. So there’s a yin and yang to genetic inheritance that is hard to fathom, even for experts.
One day, a watch that can measure a few simple things about your body will be seen as a laughably primitive tool. In the future, a whole cloud of information will be available and you must decide how much you want to delve into it. The agricultural, industrial and digital revolutions affected our environments and societies, but the genetic revolution equips us individually with new powers, and each of us will need to decide for ourselves if and when to deploy them. One way we should be preparing now is by making sure society is scientifically literate, and that our children are educated to understand risk, probability, genetic diversity and health.
Perhaps the insight to hold on to is that we are not merely our genes, our cells, our microbiome or our brain. We are all these things, but we are also more. How we see ourselves and others – the stories we tell and the philosophies we live by – are going to be just as important to our wellbeing.
• Daniel M Davis is a professor of immunology at the University of Manchester and author of The Secret Body.
Far from the Tree: Parents, Children and the Search for Identity by Andrew Solomon (Vintage, £18.99)
The Body: A Guide for Occupants by Bill Bryson (Black Swan, £9.99)
The Code Breaker: Jennifer Doudna, Gene Editing and the Future of the Human Race by Walter Isaacson (Simon & Schuster, £30)