Hypothesis is that Dectin-1 gene mutation will be more prevalent in CFS than healthy controls. Proving this will strongly suggest that a subset of CFS (particularly with comorbid IBS) is caused by a chronic fungal infection in the context of genetic primary immune deficiency (the immune system is unable to fight off the fungus). http://www.cedars-sinai.edu/About-U...re-role-of-fungus-in-digestive-disorders.aspx LOS ANGELES (June 6, 2012) – Cedars-Sinai researchers say their examination of the fungi in the intestines suggests an important link between these microbes and inflammatory diseases such as ulcerative colitis. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3432565/ Mice lacking Dectin-1 exhibited increased susceptibility to chemically induced colitis, which was the result of altered responses to indigenous fungi. In humans, we identified a polymorphism in the gene for Dectin-1 (CLEC7A) that is strongly linked to a severe form of ulcerative colitis.