lung disease genetic predisposition. asthma genetic risk. dr. anton titov, md: personalized medicine. you have recently done a major genetic study in collaboration with doctor carlos bustamante from stanford university. this study showed unexpected results (for personalized medicine). this research profoundly influences our approach to genetics of disease (and benefits of personalized medicine). it shows how people respond to medications. it also shows how personal genetics influences the risk of side effects from medications. dr. burchard: - yes. this study on personalized medicine was published in the most prestigious scientific journal "science". global media also reported around the world about your study because you have discovered several unexpected findings. please tell us about your research on precision medicine and its implications for everyone in the world when it comes to personalized medicine. dr. esteban g. burchard, md (professor of pharmacogenomics, ucsf): first of all, thank you. this precision medicine study is the result of major international collaboration. we are a part of a big team of people. we worked with community healthcare providers, with community leaders, with different government agencies, with different institutions around the world and in the united states. we studied the genetic ancestry of indigenous populations in mexico. this people in the united states are called native americans. but in mexico they are called indigenous people. it is the population that were there before columbus arrived to america. first, we demonstrated that there is a lot of personal genetic diversity among indigenous population in mexico. a native american in northwestern mexico is as genetically different from native american in southeastern mexico as much as a chinese person is different genetically from a european person. that was a huge result on its own merit (and it's important for precision medicine). but i am a physician-scientist and i am interested in factors of health that are important for practical medicine. so we measured lung function in indigenous people of mexico. lung function is very easy to measure, like persons height or heart function.
we asked the question: does personal genetic ancestry make a difference in probability of a person to get lung disease? we included data from native americans (from indigenous people in mexico) into the equations to determine if a person meets diagnostic criteria for lung disease. and we demonstrated that genetic ancestry makes a difference in diagnostic criteria of lung disease. genes played a role in as much as 10% of lung function. this is a very significant result (for personalized medicine). it changes clinical criteria for diagnosis of lung disease. it is if a person became 10 years older if we looked only at lung function. dr. anton titov, md: the difference in lung function could be as large as 10% and this is clinically important. the results of your study mean that a person may fulfill criteria for diagnosis of lung disease or the person can be considered healthy. the difference is in what is considered "normal" for such person. "normal" value of lung function usually depends on age. but "normal" value of lung function also depends on personal genetic ancestry of this person. (personalized medicine requires adjustment of diagnostic criteria for each person). dr. esteban g. burchard, md: yes. and this is important, because equations (criteria) of "normal" lung function mean a lot of patients. these equations of lung function are used to determine eligibility for surgery. "normal values" are also used to determine disability payments to a patient. these criteria are also used to qualify patients for lung transplants, for oxygen therapy and other treatments. difference of 10% in lung function is large and can change a diagnosis of lung disease of the patient. diagnosis of many different diseases - asthma, emphysema - depend upon standards of "normal" lung function. our important conclusion is that we cannot use "one size fits all approach" in medicine. we cannot simply say "because you are a european, all europeans are the same as you are". (dr. titov's note: this is a goal of personalized medicine - to tailor diagnosis and treatment for each person). dr. anton titov, md: your research study included more than 1,000 people from from many regions of mexico. your study conclusions are important for other regions of the world. northern europeans are probably very different from southern europeans.
and this is true for other regions which some people consider homogenous when they make diagnostic and treatment decisions (in era of precision medicine) dr. esteban g. burchard, md: there is a "genetic gradient" in europe between northwest and southeast. many people migrated in europe between north and south, between east and west. europeans are not all the same (dr. titov's note: understanding personal genetic diversity is key to precision medicine). we showed the genetic diversity of people in latin america and in mexico. people in mexico are a combination of three major racial groups: african, native american and european. we showed that genetic ancestry matters in medical decisions (a major benefit of personalized medicine). this is a very important finding. we repeated the study in african americans and obtained similar results. we published our results in new england journal of medicine (one of the most famous medical journals in the world). dr. anton titov, md: please tell us examples of precision medicine when individual genetic ancestry profoundly influences the risk of getting certain diseases or probability of experiencing side effects from medications. you showed in your research that genetic ancestry plays an important role in multiple sclerosis. you also showed that genetic ancestry plays a role in probability of severe side effects from a commonly prescribed epilepsy medication (carbamazepine, tegretol). please tell us more about these two examples (because they illustrate the benefits of personalized medicine). dr. esteban g. burchard, md: yes, this work is a beautiful illustration... (see next part of the interview with dr. esteban g. burchard)