Yes, that's what I concluded. My ALP is below normal. But why? I have no mutation in the ALPL gene that could reduce it's activity, so I guess there could be something else.
Did you have the entire ALPL gene sequenced, either specifically or as a result of full genome sequencing, or did you do 23andMe?
Do you know which one? Hypophosphatasia was ruled out, and the guys weren't interested in the slightest to look further although they're doing research.
I was just making a supposition based on how common the elevated B6 (and perhaps the decreased ALP) finding appears to be. But after seeing that
@wigglethemouse found that there are a very large number of presently known mutations in the ALPL gene it may be more likely that rather than there being one or two common SNPs there may be many less common ones that might have an effect. (I'm not sure if this gene might have copy number variant issues as well.)
And we're not talking here about SNPs that would actually cause outright hypophosphatasia but rather ones that would cause a relatively mild reduction in the function (or quantity) of the resulting enzyme, similar to the situation with the MTHFR SNPs, for example.
But isn't it interesting to find several people here who have the same?
Yes, assuming the increased B6 is not simply something that would be showing up more often if more of the healthy population were tested.
I've seen other publications (I can't now) where tissue B6 was not normal, but low. This seems to be the typical constellation in hypophosphatasia.
If you have a chance I’d like to see a reference that reports a different result than the one I cited. I'd have thought that if tissue levels of B6 were normal in the most severe forms of congenital hypophosphatasia with defects in ALPL that they'd most likely also be normal in other cases.
Are you sure about this? I remember that the common ALP test comprises all the ALP forms, and TNSALP is a special measurement that I encountered when hypophosphatasia was checked. (It's quite possible I misremember though, so just asking.)
Yes, you're right. I was thinking in the context of hypophosphatasia, where reduced serum ALP and increased B6 is a reflection of reduced TNSALP activity and not of intestinal ALP, for example. But what I said was wrong.
Do you maybe have a reference at hand? I'm collecting everything.
There are several that I haven't looked at more fully, but for example:
The histochemical activity of alkaline phosphatase (Al-Pase), the induction of which is one of the effects of ACTH on the adrenocortical cells...
https://www.ncbi.nlm.nih.gov/pubmed/204155/
These results suggest that ACTH releases alkaline phosphatase by activation of a phospholipase C.
https://www.ncbi.nlm.nih.gov/pubmed/15030184/