• Welcome to Phoenix Rising!

    Created in 2008, Phoenix Rising is the largest and oldest forum dedicated to furthering the understanding of and finding treatments for complex chronic illnesses such as chronic fatigue syndrome (ME/CFS), fibromyalgia (FM), long COVID, postural orthostatic tachycardia syndrome (POTS), mast cell activation syndrome (MCAS), and allied diseases.

    To become a member, simply click the Register button at the top right.

MMAB Defect Can Lead to AB12 Deficiency

Changexpert

Senior Member
Messages
112
MMAB stands for "methylmalonic aciduria (cobalamin deficiency) cblB type," which is responsible for converting coblamin to AB12. Defects in MMAB SNP's can lead to AB12 deficiency. There is not much evidence on which SNP within MMAB gene upregulate or downregulate AB12 deficiency. However, according to my source (cited below), mutation in this gene can result in AB12 deficiency.

Looking at my test result, I have homozygous conditions for MMAB G16110A (rs7134594) and MMAB/MVK A-818G (rs12314392). According to 23andme result I have, there are 18 SNP's available for MMAB gene. I am homozygous for 11 of them. This could explain why I would get surge of energy from taking AB12, but of course, more research is needed to assess the phenotype and the expressivity of these genes.

Source
http://ghr.nlm.nih.gov/gene/MMAB
 
Last edited:

Sea

Senior Member
Messages
1,286
Location
NSW Australia
Off to check my MMAB gene. I don't think it came up before when I researched cobalamin deficiency. Thanks Changexpert
 

pogoman

Senior Member
Messages
292
MMAB stands for "methylmalonic aciduria (cobalamin deficiency) cblB type," which is responsible for converting coblamin to AB12. Defects in MMAB SNP's can lead to AB12 deficiency. There is not much evidence on which SNP within MMAB gene upregulate or downregulate AB12 deficiency. However, according to my source (cited below), mutation in this gene will result in AB12 deficiency.

Looking at my test result, I have homozygous conditions for MMAB G16110A and MMAB/MVK A-818G. According to 23andme result I have, there are 18 SNP's available for MMAB gene. I am homozygous for 11 of them. This actually explains why I would get surge of energy from taking AB12.


This is good to know, I have 13 homozygous MMAB SNPs in my 23andme report.

On the G16110A and A-818G mutations do you know their specific SNP?
I did find some info altho I do could not find out how to identify the SNPs or variants listed in them as being disease related.
R186W is an example, is it an SNP, variant or something else?
http://hmg.oxfordjournals.org/content/11/26/3361.full.pdf
http://www.genecards.org/cgi-bin/carddisp.pl?gene=MMAB
 
Messages
15,786
Looking at my test result, I have homozygous conditions for MMAB G16110A and MMAB/MVK A-818G. According to 23andme result I have, there are 18 SNP's available for MMAB gene. I am homozygous for 11 of them. This actually explains why I would get surge of energy from taking AB12.
Being "homozygous" is completely meaningless. Everyone is homozygous for hundreds of millions of SNPs. It is completely 100% normal!

In order to determine if a variant of a SNP can cause problems, you have to read the research. Every single time.
 

pogoman

Senior Member
Messages
292
well I woke up after a few hours of sleep so I dug a bit deeper while waiting to get sleepy again.
fwiw Iit seems theres 3 types of methylmalonic aciduria (cobalamin deficiency).
the cblB type connected to the MMAB gene as posted and also the cblA type (MMAA gene) and cblD (formerly cblH) connected with the MMADHC gene.
I haven't had a chance to read all the links yet, 23andme shows SNPs for each altho alot of the "i" ones for MMADHC.
http://www.omim.org/entry/251100
http://www.omim.org/entry/277410
 

CCC

Senior Member
Messages
452
Would this be a possible explanation for the very large doses of adenosylB12 (and FMN) my son seems to need? We're seeing a positive effect from it: for example, the PTM (post thinking malaise) seems to have fallen away this past week.

@Valentijn - I've been wondering whether we should go down the genetic testing path to find out whether this is a lifelong thing or just transient (from induced deficiency), but I'm not sure we know enough to make it worthwhile. What's your view?
 
Messages
8
Location
Hartford, CT
DH and I are equally homozygous for every single SNP in this gene. I bet (hope) all of them are -/- :balloons: ;)
Thanks a lot, Gondwanaland, for attaching these very useful Links in your signature.
With my Heavy BRAIN FOG, Headaches, Depression, etc it will take me a LOOOONG TIME to digest any of it.
Appreciate your Effort and Sharing !!!
Now, if i could just have some GUIDANCE for my CONFUSED BRAIN, that would be a MIRACLE !
 
Last edited:
Messages
15,786
@Valentijn - I've been wondering whether we should go down the genetic testing path to find out whether this is a lifelong thing or just transient (from induced deficiency), but I'm not sure we know enough to make it worthwhile. What's your view?
I would do genetic testing ... obviously, since I did :p But it's important to understand what you get from the testing. 23andMe is sampling dozens of SNPs per gene, or just a few, or not at all, with a very good chance that relevant SNPs are not tested. But something useful might turn up, even if not causing the actual disease or providing an answer to it. If US$99 or US$199 or whatever they charge now isn't a big problem, it an easy way to look for some of the more common pathogenic SNPs.

Then there's Whole Exome Sequencing (WES), with quality tests down to around US$1000 (without interpretation). There are also gene panels available which sequence entire genes connected to certain health problems, such as B12. But those are going to be about as expensive as WES. And they are more difficult to analyze, unless you pay several hundred dollars for it, though that is something I'm trying to figure out how normal users can do it.

If your son is young, in his teens or pretty close, there's a good chance he'll recover just by resting and waiting it out. Then it might not make much difference to his health if you have genetic information or not.
 

Gondwanaland

Senior Member
Messages
5,092
Thanks a lot, Gondwanaland, for attaching these very useful Links in your signature.
With my Heavy BRAIN FOG, Headaches, Depression, etc it will take me a LOOOONG TIME to digest any of it.
Appreciate your Effort and Sharing !!!
Now, if i could just have some GUIDANCE for my CONFUSED BRAIN, that would be a MIRACLE !
I have been 3+ years looking into it and keep going...:eek: