A Polygenic score is something you can get from your DNA. Our DNA is made up of over 3 billion base pairs, letters of the alphabet, and every 100 or so spaces we all differ from each other and that’s what makes us individually unique. What we’ve found over the last two decades of research is that there are particular places in your DNA where if you carry a particular letter of the alphabet, where someone carries a different letter then your risk of heart of disease is different. And we’ve found over 200 such places in your DNA where depending on what variant you carry, your risk changes. So if you put all those things together then some people will, by chance, carry a few at risk letters of the alphabet in those spaces and others will carry a lot. And then when you look at this information you find that people who carry a lot have maybe a 5 or 6-fold higher risk of developing heart attacks.
So polygenic risk score is developed from analysing your DNA and it stratifies people into different categories of risk in the future of developing heart attacks.
So currently doctors assess risk of you developing heart attack or heart disease usually in middle age you know, when you’re in your 40s. And what doctors do is to assess whether you’ve got diabetes or high blood pressure or high cholesterol, whether you smoke, your body weight and they create a clinical risk score. And then they categorise whether you are high or low risk. And while that is useful and valuable of course for identifying people, particularly at high risk, we know that it’s not as accurate as we’d like it to be. We think that a polygenic risk score could add to that assessment, so it would increase the value you get in terms of assessing and stratifying people into different risk categories, adding to the clinical information. But more importantly polygenic risk scores can also be flagged much earlier in life because your DNA doesn’t change, so we could even in the 20s identify people who genetically are at higher risk of getting heart attacks or heart disease and therefore could adopt prevention measures for those people than otherwise is the case at the moment.