I am sorry I am a bit late with my reply but I read that you have found the interesting article that made some of us excited when posted here. Maybe one-carbon metabolism as a synonym of methylation is more familiar.
Late independent researcher Ph.D. Rich Van Konynenburg proposed that ME is caused by , not only has a connection to, a depletion of glutathione due to a blocked methylation. I shouldn´t try to present this further as English isn´t my first language, but I just wanted to introduce his thoughts. The hypothesis hasn´t been proved scientifically yet, but it works for quite a few people with ME . B12/folate protocols are used mainly by some doctors in USA . I think Dr. Sarah Myhill U.K. uses a similar protocol too. Dr. Neil Nathan and Rich Vank made a clinical study that is presented in the seminar below.
This article, I think, is the best presentation of the hypothesis (2007) :
http://phoenixrising.me/treating-cf...gue-syndrome-cfs-by-rich-van-konynenburg-ph-d
In this video recorded seminar he goes into details (2011)
http://iaomt.media.fnf.nu/2/skovde_2011_me_kroniskt_trotthetssyndrom/
There are also slides from the seminar that are possible to follow as a rather complete presentation too
http://iaomt.media.fnf.nu/networks/iaomt/IAOMT_talks_Rich_Van_K._2011__Part_1R.pdf
http://iaomt.media.fnf.nu/networks/iaomt/IAOMT_talks_Rich_Van_K._2011__Part_2.pdf
The presented treatment protocol was the actual at that time, October 2011, but was later changed a bit before Rich Vank died 2012.
There is no evidence for B12 and folate metabolism being different to my knowledge -yet. So far there is only an experience by some ME doctors ( e.g in Sweden and USA) that most of their their patients get better from rather big and frequent doses of B12 and folate. The eventual impact of MTHFR polymorphisms are investigated in an ongoing study in USA.
I hope this can give an idea of methylation issues and its , at least connection, to ME. Thank you for reading this, and for your interest in our struggles for diagnose and treatment. It means a lot to us.