Thanks so much Susan, for continuing to update our community on this important topic.SusanJ wrote:Just updated the wiki to include Chris Masterjohn's excellent post on MTHFR and methylation.
Introduction to Methylation
Re: Introduction to Methylation
Slacker
E4/E4
E4/E4
Re: Introduction to Methylation
Wow Susan, this is amazing and greatly appreciated!! I will be reading this avidly for sure. Thank you!
Re: Introduction to Methylation
I've been doing a bit more testing and research of late around my menagerie of methylation related snps, and decided to update the Methylation wiki. Here's what's new.
I reorganized the content and cleaned up the links to make the information more readable.
I added much more recent research in A Special Note about Alzheimer’s Disease and Methylation section.
And here are some new, important snps, for those of you keeping a snp bingo card.
FUT2 (B12 absorption).
The fucosyltransferase 2 (FUT2 gene) encodes a membrane protein that is involved in vitamin B12 absorption. For the common snp rs601338, the G allele is associated with lower B12 levels. The A allele of the SNP rs492602 is associated with lower vitamin B12 concentrations (− 0.06 pg/ml) among Caucasians from the US. The A allele of the SNP rs492602 is associated with lower vitamin B12 concentrations (− 0.06 pg/ml) among Caucasians from the US. The most commonly studied variant of the FUT2 gene is the SNP rs602662. The A allele carriers were at a lower risk of vitamin B12 deficiency in a population of Canadian adults. (B12 lozenges can get around the low intestinal absorption these snps cause.)
NBPF3 & ALPL (B6 status).
The snp rs4654748 on NBPF3 influences the clearance of Vitamin B6. Research has found approximately 2.9 ng/ml lower plasma concentrations of the active form pyridoxal 5′-phosphate, (PLP), in CC carriers and 1.45 ng/ml less in CT carriers. The lower vitamin B6 in C allele carriers most likely results from more efficient clearance of the vitamin. The G allele of snp rs1256335 on ALPL also produces lower plasma PLP levels as compared with the homozygous A allele, possibly due to increased hydrolysis of PLP. If you carry either snp and show lower levels of B6 (PLP), you may require higher intakes of B6.
PEMT (phosphatidylcholine levels)
Phosphatidylethanolamine N-methyltransferase (PEMT) is responsible for the synthesis of phosphatidylcholine (PC) which supplies structural integrity to cell membranes, used to create acetylcholine in the brain and used by the liver to secrete triglycerides into very low density lipoproteins (VLDL). The T allele of rs7946 is associated with low PC production. (Either choline from food or supplements, or supplement with PC directly.)
CTH (homocysteine levels)
CTH (cystathionine gamma-lyase) encodes a cytoplasmic enzyme in the trans-sulfuration pathway that converts cystathione derived from methionine into cysteine. Glutathione synthesis in the liver is dependent upon the availability of cysteine. The T;T variant of snp rs1021737 produces significantly higher plasma total homocysteine concentration. (See the hacking homocysteine section for more on fixing this one.)
Enjoy!
I reorganized the content and cleaned up the links to make the information more readable.
I added much more recent research in A Special Note about Alzheimer’s Disease and Methylation section.
And here are some new, important snps, for those of you keeping a snp bingo card.
FUT2 (B12 absorption).
The fucosyltransferase 2 (FUT2 gene) encodes a membrane protein that is involved in vitamin B12 absorption. For the common snp rs601338, the G allele is associated with lower B12 levels. The A allele of the SNP rs492602 is associated with lower vitamin B12 concentrations (− 0.06 pg/ml) among Caucasians from the US. The A allele of the SNP rs492602 is associated with lower vitamin B12 concentrations (− 0.06 pg/ml) among Caucasians from the US. The most commonly studied variant of the FUT2 gene is the SNP rs602662. The A allele carriers were at a lower risk of vitamin B12 deficiency in a population of Canadian adults. (B12 lozenges can get around the low intestinal absorption these snps cause.)
NBPF3 & ALPL (B6 status).
The snp rs4654748 on NBPF3 influences the clearance of Vitamin B6. Research has found approximately 2.9 ng/ml lower plasma concentrations of the active form pyridoxal 5′-phosphate, (PLP), in CC carriers and 1.45 ng/ml less in CT carriers. The lower vitamin B6 in C allele carriers most likely results from more efficient clearance of the vitamin. The G allele of snp rs1256335 on ALPL also produces lower plasma PLP levels as compared with the homozygous A allele, possibly due to increased hydrolysis of PLP. If you carry either snp and show lower levels of B6 (PLP), you may require higher intakes of B6.
PEMT (phosphatidylcholine levels)
Phosphatidylethanolamine N-methyltransferase (PEMT) is responsible for the synthesis of phosphatidylcholine (PC) which supplies structural integrity to cell membranes, used to create acetylcholine in the brain and used by the liver to secrete triglycerides into very low density lipoproteins (VLDL). The T allele of rs7946 is associated with low PC production. (Either choline from food or supplements, or supplement with PC directly.)
CTH (homocysteine levels)
CTH (cystathionine gamma-lyase) encodes a cytoplasmic enzyme in the trans-sulfuration pathway that converts cystathione derived from methionine into cysteine. Glutathione synthesis in the liver is dependent upon the availability of cysteine. The T;T variant of snp rs1021737 produces significantly higher plasma total homocysteine concentration. (See the hacking homocysteine section for more on fixing this one.)
Enjoy!
Re: Introduction to Methylation
And true to my methylation variant score card, I got 4 out of 5 of this set. I still wonder what my ancestors were eating that they could survive this mess o' variants.
Re: Introduction to Methylation
Maybe they just wanted to be sure they had a great-great-great (etc) granddaughter who would figure this mess o' variants out for others!!
I wonder how my ancestors on one grandparent's side thought it was a great idea to marry exclusively within one small town for generations, and often within people who were often second or third cousins!!
4/4 and still an optimist!
Re: Introduction to Methylation
You're in good company NF52. I think everyone, if they could trace all their lines back recent and distant, would find this in their family history many times over at the village level. Even marrying first cousins wasn't that unusual in village life. In some cases families of means would marry cousins deliberately to keep land within the family.
ApoE 3/4 > Thanks in advance for any responses made to my posts.