Epigenome: Do we have ghosts in our genes?
I finally got to watch Nova’s documentary on ‘The Ghost in Your Genes’ last night and was very excited to learn about the progress that epigenetics research has made in the last few years. 
As a believer that most complex diseases arise from gene-environment interactions, epigenetics has fit perfectly into a model for explaining disease risk. The work on how one identical twin can develop later in life, while the other does not, is such a prime example of how the environment can make alterations to a person’s genome over time. Researchers have underestimated (and some still do) the effect of methylation of DNA and other alternative genetic mechanisms affecting DNA expression on the risk of complex disease. This is likely why geneticists have not found strong support for genetic variants (i.e. SNPs) in their genome-wide association studies. From the perspective of a genetic epidemiologist, I have long thought that in order to determine susceptibility genes for complex disease, researchers need to look at environment effects (i.e. epigenetic influences) in the genome simultaneously.
NIH is starting to recognize the importance of understanding the epigenome and its role in human disease and recently announced the funding of several grants on this topic. Much more complex modeling and research studies are going to have been undertaken in order to start piecing this puzzle together but it is a very exciting time to see how it will unfold.
Happy Gene Hunting!
