Thursday, September 27th, 2012
Virtually every developmental, behavioral, and emotional disorder is assumed to have a significant genetic component. Autism, ADHD, depression, anxiety, addiction, dyslexia – you name it, DNA is believed to play a role. For decades, genetic research has sought to uncover the specific genes that contribute risk to all these disorders. While progress has been made – including lots of hints that certain genes may play some role for some disorders – the overall state of the field is that there is much that still needs to be learned about genetics and childhood disorders. The latest hope is that a new understanding of how the human genome may be achieved by a deeper understanding of how DNA really works, as described in more than two dozen papers recently published.
The research initiative called ENCODE is focused on extensive regions in DNA that were thought to be, well, junk. You may have heard that only 20% of DNA is actually doing something. Well the new research is showing that nearly 80% of DNA is doing something, and what’s really important is not just the genes that code for proteins, but also the vast number of genes that act as switches that turn other genes on and off. This regulatory function has been known for a long time, and it’s importance has always been grasped. What’s different now is that it seems to be a predominant mechanism with many genes devoted to it. And researchers believe that it may hold clues to understanding how many disorders arise from expression of genetic risk factors.
What is really changing is the emerging idea that it’s not so much what is in the “core” genes that directly code for things, but rather the complex mix of influences that turn genes on and off and hence influence development. Here’s where non-genetic influences – ranging from the prenatal environment to parenting strategies – may mechanistically link to how genes get expressed, or not.
You can anticipate sometime in the far, and probably near, future research studies that begin to explore this. There is certainly hope that embracing this increasing complexity of genetic systems will lead to more progress than we’ve seen in the past in terms of deliverables that either explain the causes of disorders or imply potential treatments. That, of course, remains to be seen, as we have heard lots of hype over the decades of how genetics will revolutionize our understanding of childhood disorders. We’ll need to take a wait and see approach to this – and continue to embrace interventions that are known to work right now for disorders, even without knowledge of genetic underpinnings. To that end, let’s hope that research portfolios continue to be diversified and not over-invest in genetic strategies that may, or may not, actually revolutionize treatment.