Genome studies have identified numerous genetic associations between common genetic variants (small changes in the DNA code) and risk of other autoimmune diseases; some of these genetic variants are shared between two diseases.
Cotsapas et al. Pervasive Sharing of Genetic Effects in Autoimmune Disease. PLoS Genet. 2011 Aug;7(8):e1002254.
Along with clinical evidence, this suggests that some genetic risk factors may be shared across several diseases.
In this study the investigators evaluated the extent of this sharing for 107 immune disease-risk variants in seven diseases: celiac disease (gluten sensitivity), Crohn’s disease (inflammatory bowel disease), MS, psoriasis, rheumatoid arthritis, systemic lupus erythematosus, and type 1 diabetes.
They found evidence that 47/107 (44%) immune-mediated disease risk variants are associated with multiple, but not all-immune-mediated diseases.
They also showed that distinct groups of interacting proteins are encoded near these variants in our genomes, which predispose to the same subsets of diseases.
They propose that common genetic risks and mechanisms underlie several related autoimmune diseases. The mechanisms are inferred from the proteins that occur near these genetic variants.
“Why is this important?”
“It may provide us with clues to the cause of MS and provide common treatment targets for several diseases. If we can identify an important pathway common to several disease we may be able to design a drug to target this pathway.”
“Please let me know if this post is easier to understand than yesterday’s on immunology?”
“This paper is a theoretical paper based on data already published. The term we use for this type of analysis is ‘in silico’; i.e. data mining done a computer. What this paper needs is some hard core lab work on MS’ers and control samples to see if these variants have functional consequences on the way their immune systems function.”