How about some designer jeans?

Well before you stop reading, I’m not talking about Levi’s, or D&G, or any other well-known brand.  I’m talking about our genes; those strands of chemicals that go to make up our chromosomes.  In plain speech genes carry all the information that make us who we are, and in the vast majority of cases, who and what you are, tends to be inherited. Until comparatively recently, although we understood what genes were, and how they worked, that’s about where it all stopped.

I was putting some shelves up a few months ago and managed to drill right into a plastic drain pipe buried in the wall. I had absolutely no idea it was there until water starting squirting all over the place, consequently there was a, very expensive, mess to clear up. If I had a drawing showing me exactly where all the pipes and cables were criss-crossing all over the place, then I could have chosen to drill in a slightly different position.

Put it another way, it’s a bit like looking at a nice Victoria sponge cake, and then seeing all the ingredients piled up next to it. Without the recipe it would be chance if you managed to replicate the cake. You might get it right, but it might take you a hundred goes and you still might not crack it.

A cake recipe, and a plan showing all my hidden drain pipes, pretty much sums up what the Human Genome Project was all about. It started in 1990 and finished in 2003, and now we have what amounts to the human workshop manual. This has allowed us to slowly understand much more about how we work on the inside, and whilst we are all human and so to speak, the same model, we do come in different varieties; thousands of them in fact.

So where is all this leading? The next time you have to pick up a prescription medicine you might decide to read the obligatory patient information sheet that has to accompany it. Most people don’t, and to be honest they do require a bit of wading through. But you might be surprised when you get to the bit about ‘possible side effects. I say surprised because you might be left wondering how on earth a drug with a long list of ‘possible side effects’ could ever reach the open market. Well, the answer lies in the ‘possible’ bit, the chances of you developing one of these side effects is very remote indeed, so why mention it? First the law requires it, secondly a tiny fraction of the population will probably be affected. Wouldn’t it be amazing if we could find out in advance who might suffer side effects? If we knew that we could offer them something different, and we wouldn’t have to print long lists of sometimes rather frightening side effects that in reality, for the majority, are never going to be anything to worry about.

Back to those designer genes. Codeine is a very powerful, and controlled, painkiller. Some people say it doesn’t work for them. They are not lying, because for them, codeine does not work. We know now, thanks to the genome project, that in some people their genetic makeup just doesn’t react to codeine in the same way it does in the majority of people.

It is a but of a mouthful, but pharmacogenomics is all about understanding how an individual will respond to medication. Things have reached such an advanced stage now that we seriously at the point where it will soon be possible to take a simple test to determine which drugs might not be suitable for you, in which case an alternative can be found. This is so significant from so many different perspectives; it’s a fact that an awful lot of expensive medications get wasted because they are prescribed on the basis that they work for most people. Other’s get prescribed drugs that make them worse thanks to the possible side effects. Some people end up suffering because there doesn’t seem to be a drug that suits them.

Now we can look forward to a situation when your individual genetic makeup is recorded and drugs can be tweaked to match your particular requirement. It is not science fiction anymore; we have started already.

However, until these tests become widely available the standard advice about not sharing your medication with anyone else has rather more to it than you might have first thought.

Dr Marcus Stephan

My views are entirely personal and do not reflect the view or position of any organisation. You should always consult your own medical practitioner regarding any concerns that you may have. Never stop taking any prescribed medication without first checking with your doctor.