The Causes Of Common Diseases Are Not Genetic Concludes A New Analysis
07 Dec 2010
Since sequencing the human genome, genetic researchers have searched intensively but unearthed little evidence to suggest that inherited genes cause common diseases. For such diseases, which include heart disease, stroke, cancers, diabetes, and disorders such as autism, ADHD and dementia, as well as mental illnesses such as schizophrenia and depression, significant genetic causation can now be ruled out with a high degree of confidence.
The case for a substantial role of genes in susceptibility to the major human diseases is now scientifically refuted argues a groundbreaking new analysis published by the public interest science organization, The Bioscience Resource Project.
The analysis stems from the repeated failure of a new and comprehensive genome scanning method (called Genome-Wide Association studies, GWA studies) to find important human disease genes. It notes that more than 700 GWA studies by researchers from all over the world, covering over 80 different diseases and at a cost of many billions of dollars, have yielded essentially the same result. Of the approximately 1,000 genes identified that confer susceptibility to disease only a tiny handful are of even limited importance. The remainder are so weak in their effects as to be of negligible significance to human health (1).
"Geneticists are repeatedly finding only genes with trivial effects, but since they have a strong incentive not to declare this search over, they are left invoking unlikely hiding places for the important disease genes they have always predicted," says Jonathan Latham, Executive Director of the Bioscience Resource Project (2).
The Great DNA Data Deficit: Are genes for disease a mirage? which will be published on Thursday December 9th, 2010, points out that the hiding places on which geneticists' hopes are now resting would require genes for disease to be located in places distinct from where almost all other genetic information has so far been found. These hiding places are thus scientifically highly implausible. Equally importantly, The Great DNA Data Deficit also observes that the underlying fundamental weakness of the original evidence for genetic susceptibility to disease is rarely acknowledged. "A genetic basis for susceptibility to common diseases was only ever a hypothesis," says Dr. Latham.
As the analysis also points out, the findings resolve the biggest conundrum in human health. The epidemiological data have always indicated that Western diseases are determined overwhelmingly by diet and other non-genetic factors. Similarly, clinical data have frequently shown that many diseases can be reversed or accelerated by diet and other lifestyle choices. The crucial importance of the new genomic findings is therefore to show that genetic research does not after all contradict these environmental explanations of disease. Rather, it now very strongly supports them.
"Resolution of this conflict has tremendous implications," says co-author Dr. Allison Wilson. "It means human disease is primarily of environmental and not inherited origin. It means that knowledge of the human genome is not going to fulfill most of the medical progress and therapeutic roles it was intended to. And it means that for most people personalized genomics is never going to be useful for predicting the diseases they will develop. And it also means we need to get serious about researching the broader environmental and dietary causes of all these diseases."
The authors, however, believe that the results should not be seen as bad news. "It means that our fate does not reside in disease genes. Our health is in our own hands," said Dr. Latham.
(1) For a detailed description of the failure to find disease susceptibility genes in human populations see: Manolio T. et al. (2009) Nature 461: 747-753 and Dermitzakis E.T. and Clark A.G. (2009) Science 326: 239-240.
(2) This analysis refers exclusively to a genetic basis for common diseases. It does not deny or diminish the significance of monogenic disorders such as cystic fibrosis, Huntington's disease or sickle cell anaemia that are scientifically well established. Further, as the article makes clear, there are a very few significant genes for common diseases, such as the breast cancer gene BRCA 1, that have been found.
Source: Bioscience Resource Project
Article URL: _http://www.medicalnewstoday.com/releases/210445.php
