Anyway, here is a short and sweet explanation of it
Here is the lab where some CFSers are getting their DNA tested:
Mind you the people I know that have had this done are doing it on their own and not under a doctor's supervision. Two people that I know of are tinkering with their supplements based on the results of their genetic testing. My brain is too useless to figure this out for myself so I haven't even bothered to have the genetic testing done. If I had a doc that could help me out with this whole thing I would be happy to have it done.
Here is the quite famous Methylation Protocol which I did try for a little while. I might give it another go now that I'm doing better and see if there is any further improvement. Anyway this isn't a protocol to be toyed with lightly. As Patrick over at Quixotic ME says:
Here is Rich's famous protocol (you'll have to scroll down: the last time I checked it was the 7th post on the page)
Here is my disastrous flirtation with Rich's protocol: http://infinatedays.blogspot.com/2012/06/gaston-and-methylation-protocol.html
My take on this is that if you are as sick as I am this isn't something to do on your own. Have someone with a working brain help preferably a health care practitioner of some kind. You can have a nasty potassium reaction if you miss doses of the meds or try to ween off them to fast.
EDIT: Since Blogger won't let me comment, even on my own posts, I will answer your questions here.
Rich was an engineer whose wife has CFS/ME. He developed the protocol and it works well for some. I believe that it did help me but because of my bad memory I was unable to keep up the dosing schedule with any regularity. I often missed doses entirely. For further reading on the protocol I suggest reading the message boards on Phoenix Rising website. Unfortunately we lost Rich not so long ago so he is no longer available to answer questions. He was a well respected member of the CFS/ME community.