MTHFR and maths. Adding a dose of realism.

[fbirder]

Many people post saying they have a mutation in the MTHFR enzyme and suggest that this is to blame for their problems. So I did a bit of thinking.

First off - there is evidence from proper studies that people with two copies of one particular mutation (called C677>T) may have problems with production of methylcobalamin and might require supplements with methyl folate to get round the problem.

Apart from that there is no real evidence. Lots of speculation, but no evidence.

One subject of this speculation is the A1298>C mutation which some say can cause problems if somebody has one copy of each of those mutations. But about half of all people have at least one copy of C677>T and half have A1298>C. That means that a quarter of people have at least one copy of both. More interestingly, perhaps. Three quarters of all people have at least one of those two mutations.

Let's not stop there. The DNA analysis tool Promethease lists 12 known SNPs (Single Nucleotide Polymorphisms - known mutations). Of those, it lists the percentage of wild types (non-mutated) for each SNP. They range from 39% to 89%.

You can use those figures to calculate the proportion of people that don't have any mutations.

The chances of having a mutation in at least one of these 10 SNPs is...

1 - (0.5 x 0.44 x 0.39 x 0.46 x 0.49 x 0.62 x 0.69 x 0.69 x 0.76 x 0.89) = 0.996

That means that a mere 4 people out of 1000 do NOT have a MTHFR mutation.

So, next time somebody says they have a MTHFR mutation you can tell them that almost everybody does.

[Sleepybunny]

Some links about MTHFR mutations

MTHFR/ migraine

bmcmedicine.biomedcentral.c...

MTHFR /thrombosis

onlinelibrary.wiley.com/doi...

MTHFR/mental health disorders

ncbi.nlm.nih.gov/pubmed/211...

[fbirder in reply to Sleepybunny]

Thanks for those links. I've been doing some looking and found a couple more positive results. While each study shows just a small increased risk if you are homozygous for C677>T every little bit will add up.

So I would now recommend that anybody tested positive for that mutation should consider taking 400 ug of methylfolate every day. It can't hurt and it might do some good, for a small extra cost (roughly 90p vs 30p per tablet).