Report Blog On Mthfr Genetic Defect in Dysautonomia Discussion Posted January 24, 2015 Well it is associated with many medical conditions, including autoimmune disease. My dysautonomia is due to the damage done to my small fiber nerves as a result of autoimmune disease. Is the mthfr gene the one the caused my particular autoimmune issues, don't know, but maybe. It might be another gene I don't know about. Since I have one bad one I may have more. There is a lot of research going on with it. My cardio is who tested mine as it's associated with some cardiovascular disease.The good news is it's easy to bypass. Cut out all foods and supplements that have folic acid the inactive form of folate and supplement with the methyl or active forms of the Bs. Eat lots of fruits and vegetables, folate is already in the active form in those foods.