At Queen Mary University in London, researchers have conducted the largest study of genetic sequencing of human diseases known to date, identifying the genetic basis of six different diseases: autoimmune thyroid disease, celiac disease, Crohn’s disease, psoriasis, multiple sclerosis, and type 1 diabetes. For these diseases, the exact cause is not known, but according to the study, it was believed that the diseases were a complex combination of both genetic and environmental factors. For each disease, there was only a small portion of hereditability is explained by genetic variants.
    In past studies and experiments, genetic variants were only identified as weak-effect. For this study, global scientists used highly throughput sequencing techniques in order to identify new variants, along with rarer and higher risk variants. In a previous experiment that contained twenty-five risk genes, the risk genes were found in a sample of nearly 42,000 individuals, 24,892 of the individuals with autoimmune disease, and 17,019 individuals were controls.
    Within the May 2013 edition of the journal Nature, scientists suggest that the overall genetic risk of these diseases more than likely involves a complex combination of weak-effect variants which are common in the overall human population. David van Heel, Professor of Gastrointestinal Genetics at Barts and Queen Mary University, led the study, saying that there is a lesser risk of autoimmune disease from a few high-risk genetic variations, and a greater risk of random selection from the common genetic variants, each having a weak effect. Heel goes on to say that the genetic risk likely comes from inheriting a large amount of common variants from both parents. This would mean that it would be nearly impossible to test individually for such diseases. However, scientists are started to grasp the biological basis for the conditions that cause these diseases, opening a pathway for researchers to follow, hopefully leading to new drug avenues and possible treatment options.

By Lauren Horne
Sources:
    Queen Mary, University of London (2013, May 22). Largest genetic sequencing study of human disease. ScienceDaily. Retrieved May 23, 2013,
 
 
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