MTHFR and other methylation mutations

According to Dr. David Kaufman of Open Medicine Institute, diagnostic markers for ME/CFS include low natural killer cell function, low vasopressin levels, mutations of the MTHFR gene, and abnormalities of the HPA axis:

http://www.nytimes.com/2015/02/25/opinion/understanding-chronic-fatigue.html?_r=1

Note that by this definition, the infectious agent involved does not define the disease; indeed many people have many reactivated pathogens only revealed upon careful and reliable testing, including, herpes viruses, parvovirus, lyme, babesia, bartonella, etc.

For infectious disease testing, the following sites are useful:

https://sites.google.com/site/cfstestingandtreatmentroadmap/

http://med.stanford.edu/chronicfatiguesyndrome/infections.html

http://www.columbia-lyme.org/