Tracking my efforts to beat Myalgic Encephalomyelitis (ME), aka CFIDS, aka CFS

Tracking my efforts to beat Myalgic Encephalomyelitis (ME), aka CFIDS, aka CFS

Thursday, March 14, 2013

Nutrigenomics: Addressing CBS & BHMT mutations

In this post, I compile a list of six clues to determine if CBS & BHMT mutations are an issue for those of us who have heterozygous CBS & BHMT mutations and, therefore, aren't sure if we are up-regulators.  This list is compiled from Dr. Yasko's book and the Methylation section of the Heartfixer website, where each clue is mentioned in different areas, but never compiled as a list .

For those of us that decide to go the nutrigenomics route to treating ME/CFS, one of the first problems we encounter is deciphering whether CBS & BHMT mutations are problematic. These two mutations are up-regulations, leading to high levels of sulfate and ammonia.  As Dr. Yasko puts it, this up-regulation leaves the "drain open" meaning that any other methylation supports will go "down the CBS drain" if the CBS mutation is not addressed first.

If you are homogygous (+/+) for any CBS mutation, there is no question that you are affected.  But there's ambiguity for those of us who are heterozygous (+/-) for the CBS mutation, especially if it's the lesser of the two mutations: CBS A360A.  (Note there are also some people who believe that Dr. Yasko is incorrect and that CBS mutations are not important.  See posts #17-19 in this PR thread.)

Six Clues

Urine sulfate levels:  Urine sulfate levels can be tested at home using these urine sulfate test strips.  Ideally, you want your urine sulfate levels below 400, but if that's not possible, then below 800 is apparently acceptable. (Heartfixer, see Overview, #2).  Mine is testing around 800.  CONCLUSION: SLIGHT PROBLEM.

Blood ammonia levels:  If blood ammonia levels are high or high-normal, it tends to indicate CBS or BHMT issues.  Mine tested at the highest possible number without being out of range: 47 (normal range is ≤47 ┬Ámol/L.  CONCLUSION: PROBLEM

Sulfur Tolerances:  If someone has a CBS and/or BHMT mutation, supposedly they will not tolerate sulfur well.  This means they will have an adverse reaction to foods or supplements containing high sulfur.  For me, I have never noticed any adverse affects from eating eggs, broccoli, and other foods high in sulfur.  (It's not clear what the adverse reaction would be).  Also, I underwent a heavy metal detoxification protocol last September using DMSA, which contains high amounts of sulfur.  I did not have any adverse reactions.  CONCLUSION: NO PROBLEM

Blood homocysteine levels:  Supposedly, the CBS mutations usually lead to low or low-normal levels of homocysteine.  I've never seen "low" defined, but optimal levels are considered to be around 6 to 7, so "low" is obviously below that.   Mine, when tested last in December, 2011, was 9.1, which is within range, but above optimal.  (Reference range is <14.4)  This might suggest that I don't have CBS or BHMT mutation issues, except for the fact that I have other mutations SHMT (+/-), MTR A2756G (+/-), and MTRR A664A (+/+) which lead to high levels of homocysteine.  So it's possible that these other mutations are counterbalancing the CBS up-regulation.   CONCLUSION:  UNCLEAR

Which CBS mutation?:  As mentioned above, the CBS A360A is the least severe of the CBS mutations, leading to only about 1/40th the amount of up-regulation as the CBS C699T.  Further, if you are heterozygous (+/-) like me, it's not clear if that particular mutation is "turned on."  CONCLUSION: UNCLEAR

Combinations of mutations:  Someone who only has a CBS mutation or only has a BHMT mutation is less likely to have a problem than someone who has both.  Personally, I am heterozygous for CBS A360A and 3 of the 4 BHMT mutations: 2, 4, and 8.  (1 is not tested by 23andMe).  CONCLUSION: LIKELY PROBLEM


It's still a little unclear, but to be safe, I'm going to assume that I have a slight to moderate issue with CBS up-regulation, and cut down a little on the highest sulfur foods, but I won't radically change my diet.  I will also supplement with Yucca and charcoal flushes before proceeding to the next phase of the methylation protocol.

[updated 5/23/13]

[5/28/13]  This thread from Phoenix Rising provides some interesting feedback from other users trying to   treat CBS and BHMT mutations.  


  1. Hey Patrick, did you get my email (mathtutor)?

    1. Hey David, actually I don't think I did. Sorry, I even checked my spam folder and nothing was there. Could you maybe send it as a PM on HealKick?

  2. This comment has been removed by the author.

  3. Hello Patrick!
    I must thank you for this great blog.
    Now i wish to get your opinion from that whey protein-90 isolate, i have eat it and now you have list what must eliminate from diet. There was also whey protein concentrate. Can you say why it is bad? What mechanism or something? No i do not touch it.
    Lisbeth from North

    1. Hi Lisbeth,

      Thank you for your comment. According the the book "Autism: Pathways to Recovery" whey protein isolate is an "excitotoxin," meaning that it overstimulates nerves in the brain, causing damage to the nerves. I don't know if this is true, but I believe that the author of the book is probably correct.

      Best of luck,


    2. Hi Patrick!
      Big thanks, i thing that everything must be natural. In this protein i have pondering that hole process production and orginal source. Now i close this pot. Now i must think more.

  4. Patrick, I am CBS A360A +/-, +/+ for BHMT01 and BHMT08 and many others. Regarding sulphur and ammonia issue. It appears I might have issue with sulfur and ammonia. I think you asked what might happen if you had this issue. Well for me I end up getting extremely fatigued, brain fog, histamine like reaction, my body and brain shut down from 3-14 hours before functional again. If you have an issue with sulfur and ammonia I believe it is an unmistakable physical response.


    1. Thanks for that information Roxie. I certainly get extremely fatigued and brain fogged, but it's hard to say if that's just because I have ME/CFS or if that can be particularly pinpointed to sulfer and ammonia issues.

      Good to meet another person with similar SNPs

  5. So, did your doctor run the blood ammonia and homocysteine tests for you? I bought the urine strips from your link. Being sick is expensive!
    I, also, have no idea if my high-sulfur diet is causing any of my symptoms. Did you cut down on meat?

  6. Sorry, I meant to ask, you supplemented with yucca? How did that go? How much? And how do you do charcoal flushes? Feel free not to answer these, I can Google... but I trust you. :-)

  7. i have CBS A360A (+/+) but have very low urinary sulfate on multiple organic acid tests. after reading a bunch, i am starting to think the A360A mutation is not a big issue. i also have no poor reactions of any kind to sulfur rich foods. nutrigenomics is in its infancy, but it will be interesting to see how it progresses in the future. good luck to you.