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Couple of questions

Discussion in 'Genetic Testing and SNPs' started by dbkita, Apr 10, 2013.

  1. dbkita

    dbkita Senior Member

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    Hi all,

    A couple of questions that have been bugging me for a long time:

    1) Does anyone have any research articles that back up the claim by Dr Yasko and others that a homozygous CBS C699T mutation up regulates enzyme activity by 10x or anything close to that.

    Stuff I have seen so far which looked at homocystiene levels of people with and without the mutation showed fairly nominal variations (i.e. like 10-15% or so reductions in those with the mutation). Nothing close to the heavy up-regulations claimed by Dr Yasko et al.

    2) Has anyone seen a source other than Dr Yasko or Heartfixer that confirms that sulfates increase the fight or flight response? And if so, what is the explanation given?

    Thanks ahead of time.
  2. Victronix

    Victronix Senior Member

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    Good questions. Please post if you ask them and they respond (assuming no one else has the answers on here).
  3. PDXhausted

    PDXhausted Senior Member

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  4. dbkita

    dbkita Senior Member

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    Thanks for the link.

    This is all I have found so far (I think different paper same authors):

    http://hmg.oxfordjournals.org/content/10/6/635.long

    Ironically they are talking about CBS deficiency here ... but I have not had time yet to thoroughly read it.

    The reason I am asking is so far from what I have seen of post methionine loading studies, the CBS C699T SNP does not have large impact in humans (not yeast) on levels of homocysteine. So yeah I am confused.
  5. sianrecovery

    sianrecovery Senior Member

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    I find a fair bit of Yasko confusing. I also find the certainty with which the results of testing are interpreted and sent with a list of expensive supplements of hers that will help unedifying.
    abporter and Valentijn like this.
  6. caledonia

    caledonia

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    In her Vimeo video, Methylation and Mutations part 4 of 5, about 21 minutes in, she references: Influence of 699T - C and 1080C - T Polymorphisms of the Cystathionine Beta Synthase Gene on Plasma Homocysteine Levels http://www.ncbi.nlm.nih.gov/pubmed/11149614

    It looks like you will need to read the whole article, not just the abstract to find the "ten times upregulation" information, although she does show the relevant part in a slide.

    There was a thread on here with a similar question about the CBS upregulation leading to a cortisol/stress response. We did figure out that alpha-ketoglutarate is not produced as shown on older diagrams like on Heartfixer. It's something with a similar name which, of course, I can't remember. Yasko has since corrected it on her newer material.

    However, the mechanism by which the upregulation leads to the stress response is still a little fuzzy. There's probably some study somewhere that Yasko references to show this, but I haven't found it.

    However, empirically, with myself as the subject, it does all seem to work as she says. I'm CBS C699T +/- and did have a terrible time tolerating methylcobalamin. At one point, I could only tolerate 0.5mcg of mB12 without feeling stressed and anxious. When I stopped the mB12, that feeling went away within a day or two. When I restarted it came back. My urine sulfate tested 1200 (high).

    I did the CBS protocol for several months to lower ammonia and sulfur. My urine sulfate is down to 400-800. Now I can tolerate a much larger amount of mB12 with no problems. I no longer need to take yucca or charcoal, or limit free thiols (sulfur) in my diet.
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  7. dbkita

    dbkita Senior Member

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    Thanks for the link.

    In the other thread we agreed it was alpha keto butyrate not alpha keto glutarate, very different things.

    Here is an interesting link by the same author:

    http://www.researchgate.net/publication/12856164_Relation_between_plasma_homocysteine_concentration_the_844ins68_variant_of_the_cystathionine_beta-synthase_gene_and_pyridoxal-5'-phosphate_concentration


    Note it is a different SNP. But basically the up regulation was exacerbated when the p5p concentration was LOW not high. Which is surprising since p5p is the cofactor for CBS. Suggesting something else is in play perhaps.

    Please not I am not questioning the link of CBS activity and trans-sulfuration by products. I am questioning the amount of up-regulation purported by the SNP in question. SAMe is an allosteric modulator of CBS that increases activity already 2.5-5x.
  8. dbkita

    dbkita Senior Member

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    Alright I have read the paper that Caledonia linked and I believe is the same one sourced by Yasko in the pdf that PDXausted linked. And when I get a chance I will comment on it. But the summary is: unless I am missing something the paper and others like it suggest the impact on homocysteine levels is NOT that large though it may be enough to have clinical impact on the trans-sulfuration pathway. Going to take a while to round this all up and process it properly just like when I had to wade through the VDR allele debacle. I also fear that again the C699T SNP is maybe PART of a fragile haplotype but until we know all the other pieces we are in the dark somewhat. Personally I know that when I eat a LOT of meat I get more pain and anxiety which hints at an ammonia problem related to excess sulfur. Again my question was regarding the 10x factor Yasko claimed. Thanks all for the links. If there are any others that would be great so we can properly circle the wagons.
  9. dbkita

    dbkita Senior Member

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    I have yet to read one more paper to be certain of my conclusion. Have to download at work using scifinder. But basically Dr Yasko took s statement from a paper out of context when quoting the 10x up regulation. The authors were talking about an engineered deletion of 145 residues containing the c terminal regulatory domain leaving the catalytic doma in wide open in yeast. On top of that the massive deletion is not sensitive to SAMe as an allosteric agonist so when compared to wild type it would be only 3-4 X when SAMe is present. But that is moot since the Yasko methylation SNps for cbs are two silent missense mutations in exon 6 and 10 in the same regulatory domain and while they lower plasma homocysteine post methionine loading four hours later by at most 10 % or so (unless you triage the data heavily and then it rises to 20%) they are nothing like the huge engineered deletion. The scientists engineered the special mutant to answer fundamental questions in a clever and commendable way. But then this was taken out of context and misapplied to yhe clinical setting. My guess is the pml changes of 10 % or so in homocysteine are the clinically relevant part to possible sulfite and ammonia problems. But it ain't close to 10x activity increase. Another example of a bad mixing of snps at a theoretical level and the clinical setting. Raises the hackles on the back of my neck.

    Anyways I will verify in one more paper directly sourced by Dr Yasko in the pdf that was linked but unless people are interested in a thorough analysis I will focus on other questions as I have my answer for my first question and it is time to move on.
    Valentijn likes this.
  10. dbkita

    dbkita Senior Member

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    Sigh read the final "10 x paper". Dr Yasko and her team completely misinterpreted their paper. The truncated mutant version which has nothing to do with the measured SNPs on the Yasko panel has a ten fold activity over the wild type when NO SAMe is present. When SAMe is present, the truncated mutant barely changes but the wild type jumps by like 7-8x. So the truncated version is essentially always "active" at a level maybe 30-40% more than the wild type when SAMe is bound at the allosteric regulatory site. Again though this is with the ENTIRE C-terminal regulatory domain being cleaved off via introducing an artificial stop codon. The myth that has perpetuated by Yasko and her camp of a 10x activation difference with homozygous C699T is nothing short of bad science. Period. Ick.

    For all the people out there who are concerned about CBS homozygous mutations, yes there are 10-20% over conversion of methione into homocysteine post methionine loading that can potentially increase trans-sulfuration flux but it is NOT the 5-10x garbage that has been floated.
    abporter, Sea, helen1 and 1 other person like this.
  11. dbkita

    dbkita Senior Member

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    No comments, eh?

    Well let me know if you have any questions. Otherwise I will move on. Though I still have not found any evidence to answer the second question. I would love to hear from those who follow the Yasko protocol what their thoughts or understanding is.

    But take heed:

    The assumption of 5-10x upregulation with a CBS C99T homozygous mutation is patently 100% WRONG.

    I can't tell you the exact amount of upregulation but I can put pretty firm constraints on it via the many
    Post Methionine Loading studies. And the effect is not very high. And btw is essentially almost NOTHING for the heterozygote case. So while I don't dispute trans-sulfuration flux can cause problems, the dysregulation is likely due to epigenetic factors or some other genetic haplotype that we as a civilization know nothing about.

    Good luck!
    abporter likes this.
  12. ahmo

    ahmo Senior Member

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    Hi dbkita. I've been following this conversation, though I can just barely follow the science. It's great that you tracked this thing down. Thank you. I'm following Yasko protocol generally, not rigidly. I think her work is excellent, and it's also really important to find these glitches in her info/thinking. Like her understanding that glutamine forms glutamate, that sulfurous foods = thiols, and that hydroxycobalamine is useful. BTW, someone suggested ornithine to me for reducing ammonia. My body tests very + for this, and I've been able to stop the yucky yucca tincture I'd been using. cheers, ahmo
  13. PDXhausted

    PDXhausted Senior Member

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    Thank you for reviewing these studies! It is nice to have an unbiased party reviewing this stuff. I did want to say earlier that she doesn't even mention the 10x figure in her Pathways to Autism book, but rather mentions that the mutation has "40x increased enzyme activity in animal studies", but I couldn't find a reference anywhere for that figure, and it is probably another not great study anyway, since it is not human.
  14. PDXhausted

    PDXhausted Senior Member

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    Oh and regarding the study from reply #7, that was an interesting find on the P5P... I'm curious to know if anyone with CBS mutations has had issues with B6/P5P exacerbating their CBS symptoms, or not?
  15. dbkita

    dbkita Senior Member

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    So the ornitihine has been helping you? Good to know. Cheers to you :)
  16. dbkita

    dbkita Senior Member

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    I don't think the 40x would be relevant simply because it is likely a controlled artificial mutation like the one where 145 amino acids are cleaved out. Good for research purposes but useless to us clinically. What we care about for Dr Yasko's claims are the SNPs tested in her panel. Anything else is conjecture and highly speculative. But misapplying data from a perfectly valid study and taking it so far out of context is not good imho.

    Btw here are the papers I read:

    http://www.ncbi.nlm.nih.gov/pubmed/9590298
    http://www.ncbi.nlm.nih.gov/pubmed/11149614
    http://www.ncbi.nlm.nih.gov/pubmed/11230183

    The first is the one referenced in the pdf link by PDXausted. The second is the one referenced in Caledonia's link.
    The third is one I came across that studied different mutations. I also found several others that back up the 2nd paper in regards to post methionine loading.

    Again I want to point something out. Those people in the 2nd paper had 7 grams!!!! of methionine loaded. I eat a lot of meat a day, about 200+ grams of protein, and I get 6-7 grams of methione + cysteine a day total spread over the entire day in four meals. So they gave a really large infusion of methionine (I say 7 grams since they used 100 mg per kg bw and I am roughly 70 kg). And the difference for the dreaded C699T SNP homozygous was 10+ % until they further restricted to other non-mutant haplotypes but then the (geometric) mean of the controls went up, thus rendering the 20% figure. There was no real association of the C1080T until they again isolated groups with no other sampled mutations.

    They even reference in their paper another article that already showed no association of significance. They try to argue in their favor why the difference but the one could counter-propose that the real reason is the other paper did NOT split out other mutant sampled SNPs. The splitting does not help us since we don't know the other SNPs for our genomes.

    So at best we are talking 10% at least for what we KNOW.

    That means a difference of 10% in homocysteine getting turned by CBS into fodder for the trans-sulfuration pathway. That is nowhere near 10x, 5x, 2x, etc. I would assert that 10% delta can cause issues downstream. I also assert that the impact for these two SNPs for a heterozygote is most likely null and void unless it happens to be part of additional SNPs for a fragile / broken haplotype we know NOTHING about.

    Note to put things in perspective you can probably alter the flow by 10% through the CBS gate by simply increasing p5p / b6 (doubt response is linear) in a normal dose regime. Please let that sink in. Again I doubt the dose response is linear but I am pretty sure my argument is sound.

    CBS is a p5p dependent enzyme after all and they use huge doses of b6 for homocysteinuria sufferers. Personally if I double my dose of p5p to 50mg I get destroyed with muscle pain and fatigue and bad moos.

    So yeah the next time you look at a sulfate strip or are suffering from ammonia, instead of only blaming the meat (methionine / cystein) ALSO take a long hard look at your b-vitamins and a long hard look at your gut for possible dysbiosis. At least that is my opinion.
  17. fozzaw

    fozzaw

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    Andy Cutler has written for a long time that high cysteine (resulting in thiol intolerance, whether food or supplements) is a side-effect of mercury toxicity. His records are that 1/3 of heavy metal toxic individuals are intolerant of thiols, 1/3 feel better with more, the rest are in the middle. People also have stated that cysteine levels have fallen as they have healed during chelation using his protocol. This contradicts Yasko's claim that CBS mutations are the reason for thiol intolerance.

    P5P definitely exacerbates thiol intolerance in multiple people I know who are high cysteine.
    Anything that increases thyroid activity (if hypothyroid) will do the same.
    Molybdenum and manganese have helped me and another person with increasing thiol tolerance.
  18. cobain_justinsane

    cobain_justinsane

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    Hey Everyone:

    So what is the general conculsusion that is being presented in this forum?
    -Is a CBS mutation really a problem when treating MTHFR/Methylation blocks especially if one is only heterozygus for the C669T mutation?
    -What evidence is there that CBS pulls Methyl B12 &Methylfolate down the "CBS Drain"?
    -What effect does P5P have on CBS?

    Sorry if it's already been laid out here, but I have trouble following the science laid out here and need it put in simpler terms that are easier to understand.

    I am concerned about the CBS but am quite eager to begin on Mfolate & B12 but am just worried about some of the effects it may have on me with the CBS heterozygus.

    Thanks for any imput!
  19. dbkita

    dbkita Senior Member

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    a) CBS enzyme will tend to process excess methyl donors and sulfur containing amino acids down the trans-sulfuration pathway. This is not in question. The question is how much activity change is there based on CBS mutations relative to a person with the wild type. The answer is maybe 10% or so for a person with C699T homozygous and little to none for a person with the heterozygote. However, we are talking relative here. So a person who ingests or produces a lot of methionine or cysteine or thiol containing foods may still be at risk. However, the PML studies show a roughly 2x jump in homocysteine 4 hours after loading 7 grams of methionine which is probably more than most get in a day.

    b) Refer to a) above and please read the posts talking about post methionine loading. CBS does not "pull" methyl b12 or methylfolate specifically. It "pulls" homocysteine which is made from SAMe and in turn from methionine and in turn from methylfolate and mb12. A review of the methylation cycle may help to better understand this. You can google for diagrams of the folate and methylation and trans-sulfuration cycles.

    c) p5p is the cofactor for CBS. Raise p5p and depending on dose response curve you will almost certainly increase CBS activity perhaps up to some saturation point.
  20. dbkita

    dbkita Senior Member

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    Thiol intolerance and trans-sulfuration issues while related need not be the same thing. Post methionine loading is a real effect and will increase trans-sulfuration flux on its own as will cysteine intake. The idea that intake of thiols is the ONLY source of trans-sulfuration flux is non-sensical. The relationship between cysteine and mercury I will leave to Dr Cutler. Intake of cysteine or as the result of thiols will obviously raise trans-sulfuration activity.

    However, many of us on these forums do NOT have mercury issues and yet still show signs of trans-sulfuration problems. So I don't agree that Cutler's theories contradict Yasko claims. They may be two different things. Again Cutler's assertion don't have any relevance for many of us who have no toxic metals but have trans-sulfuration defects nonetheless.

    Please understand that my dispute with Dr Yasko was over her 5-10x assertion. That too is nonsensical. But ... differences of 10% or so in plasma homocysteine levels for homozygous CBS mutations post methionine loading may still be a LARGE enough flux to pose problems with ammonia and sulfites. We are again talking relative to a person who has the wild type. Say both sit down and eat a huge steak dinner, we wait several hours and voila one has lower homocysteine due to their CBS mutation but at the same time higher levels of one or more transsulfuraton products presumably. That is the standard of comparison. Not other routes into the trans-sulfuration pathway.

    One mechanism so that p5p enhances thiol intolerance is CBS activity is increased, so more flux on top of what is directly being transplanted by raising cysteine. On the other hand molybdenum or manganese will help anyone with trans-sulfuration issues in principle since one helps with processing sulfites and the other with clearing ammonia in the urea cycle.

    My point is that thiol intolerance leading to high cysteine levels via whatever mechanism is just another route into the trans-sulfuration pathway. Another is driving of the methylation cycle and the more excess methionine produced the more flux presumably down through CBS and hence more cysteine again. But the downstream results will be similar.

    If I use urine sulfate strips as a biomarker, both large consumption of protein and eating servings of broccoli, asparagus, etc. lead to higher levels of excreted sulfates several hours later. For me I eat three to four large servings of such vegetable a day on my 3500-4000 calorie diet. But I consume 200-225 grams of protein a day, leading to a total of 6-7 grams of methionine + cysteine ingested per day. Personally if I add a couple of grams of M+C to my intake via say eating a steak I get a larger bump 3-4 hours later than if I eat more vegetables. So while both effects are present, the high protein is a bigger factor for me. That being said, the single biggest way to bump my urine sulfates up is to take more p5p. Going from 25 to 50 mg raises my urine sulfates by about 50-75%. Hence my point that a 10% difference in flux for a homozygous mutation can easily be simulated in a wild type person by upping p5p. I think therefore bigger issues are functioning of SUOX and urea cycle which is where molybdenum and manganese come into play. Note raising methylfolate also raises my urine sulfates.

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