Humans are all almost exactly the same... almost - Greg Foot

Medical science has a problem—it’s missing something. Something that means that not only is it harder to find the causes of some diseases—and effective ways to treat them—some diseases are getting overlooked entirely. It turns out what it’s missing could be you—but I’ll get to that in a bit. Because first, a story. Or 8 billion stories, to be precise.

See, our DNA is our body's instruction manual, sure. But it’s also a history book that records our own, unique genetic story. All our stories begin around 300,000 years ago when humans arose in Africa. Some genetic stories tell of leaving a couple of hundred thousand years later, journeying into Europe, East Asia, or the Americas. Some genetic stories speak of expanding empires. Others the diseases we evolved to ward off, and some the simple act of settling down, raising cattle, and drinking their milk.

Each of our genetic stories are different, but maybe not as different as you might expect. We share 99.9% of our DNA with each other. Our stories are 99.9% identical, but that 0.1% difference is incredibly powerful. In that tiny difference between our genetic stories is where we have the potential to develop better treatments for diseases—treatments that work for everyone. But medical science isn’t currently reading all those stories.

To explain, let me tell you how researchers work out the causes of diseases, and develop and test the effectiveness and safety of new treatments. To find out the causes of a particular disease, researchers find lots of people who have that condition and comb through their genetic stories. They look for little variations they share—little bits of their DNA stories that are spelt differently. If they find some, then they try all sorts of different ways of dealing with the effect of them.

And if that uncovers something that looks promising, they then run a clinical trial to see if it actually is. In phase one, a small group of volunteers try the treatment. Well, often only half of them do, with the other half getting a placebo that does absolutely nothing. If there aren’t any notable side effects at the target dose, the treatment is cleared to move on to the next stage of the clinical trial.

Phase two, this time with a bigger group of participants who all have the condition the researchers hope the drug will treat. If the drug appears effective, it moves on to phase three, with more participants trying it for even longer. Only after all this is the new treatment then reviewed and—hopefully—approved for use by us, the general population. But there's a problem with it.

Here is the ethnicity of lots and lots of people used to recently find the causes of various diseases. And here is how that compares to the ethnic diversity of the world’s population. Spot the difference? The genetic stories that researchers are combing through are heavily biased to those of people from European descent. Which means that if you’re searching for those disease-causing bits of DNA to target new drugs against, and you're mainly reading the stories of people of European descent, you might completely overlook key bits in the stories of other diverse groups that tell of, say, a changed risk of disease or even shed light on how a disease occurs—for example, scientists may not have found the mutation that causes sickle cell disorder if we’d only looked in the stories of people of European descent.

And the thing is, what medical science is missing doesn't end there. When new treatments or medical devices are being tested, they need to be tested on everyone that may use them. If the genetic stories involved don’t reflect the breadth of stories in our worldwide library then, again, something might be missed.

Take, for example, the medicine Warfarin; used to prevent blood clots. Researchers have found that, to produce the same effect, most people of East Asian descent need a lower dose than some people of European descent, and most people of African ethnicity need a larger dose. Which means the dose that works best for someone may vary according to their ethnicity. It’s this kind of important information that can be missed if clinical trials don’t include people from across a range of ethnicities.

So what’s the solution? Well, it’s quite simple... in theory. In order to develop treatments that work better for everyone, we need to involve everyone’s stories in medical research—in the early stage research, in the drug development process, and right through the clinical trial.

The good news is that more and more people are thinking about this. For example, cancer researchers at University College London researching genetic markers for cancer want to analyze tissue samples from a wide range of ethnicities so that the biomarkers of cancer they identify will be relevant for people from as many ethnicities as possible.

Bottom line: medical science needs to ensure it’s got the best library it can have—the one with the widest collection of genetic stories possible, so that everyone’s story can be considered—including yours. That is the only way to ensure everyone, everywhere can get the best medical treatment they possibly can.