How will epigenetic developments transformmodern healthcare?
Samuel Omotosho
For centuries, scientists and philosophers have grappled with the concept of whether our ‘nature’ or ‘nurture’ is the predominant force in shaping who we develop into as people. While our inherited genes are clearly responsible for certain physical characteristics such as eye colour, the role of genetics in determining our personalities and our physical and mental health is more debatable. Those who advocate the nurture theory stress the importance of our environments – including various aspects of our lifestyle and upbringing - in shaping these complex characteristics. On the other hand, supporters of the nature theory have emphasized the influence of genetics in our lives. The modern consensus recognizes the importance of both genetics and the environment in establishing our complex physical and mental profiles. For instance, while correlations between weight and activity levels are obvious, there also appears to be a link between obesity and carriers of the FTO gene. 1 The burgeoning science of epigenetics is challenging how we frame this debate surrounding the influences of nature and nurture on our lives. Rather than seeing the environment and genetics as competing influences, this field emphasizes their interconnectedness and has demonstrated how our environment can directly influence our genes. Lifestyle choices and environmental conditions cannot change an individual’s genetic code, but they do prompt epigenetic processes that modify how our genes are expressed. Although the genes we are born with will remain with us throughout are lifetime they can effectively be turned on or off via changes that can be inherited across several generations but can also be reversed within a lifetime. There are several epigenetic processes that moderate gene activity, but DNA methylation is among the best understood and involves CH 3 methyl groups attaching to genes and suppressing their activity, 2 leading to either beneficial or detrimental effects on an organismdepending on the gene ’ s function. The medical applications of this knowledge have the potential to transform the way we treat disease. Designing epigenetic interventions to target specific genes could represent the future of how we treat the conditions that afflict many of us today, including cardiovascular diseases, brain disorders and several cancers. Our understanding of epigenetics has been propelled by a series of experiments on rodents and observational studies with humans, transforming how geneticists have viewed genes and inheritance. A landmark study on agouti mice by Duke University scientists marked the birth of modern epigenetics and demonstrated how connected our environment and genetics could be. Mice with the agouti gene are fat, yellow, and more susceptible to develop diabetes and cancer but, in the experiment, after they mated, the offspring of pregnant mothers who had been fed a diet supplemented by certain vitamins were thin, brown, and healthy. These offspring shared the dangerous agouti gene of their parents, but its expression had been silenced and its consequences erased. 3 This occurred because there were certain compounds in the vitamin supplements that were methyl donors and had attached to and silenced the agouti genes in the embryos of the expectant mice. 4 Epigenetic processes were later shown
1 Peeke 2014. 2 Genome.gov 2020. 3 Watters 2006. 4 Moalem 2007: 163.
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