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I must confess to having followed this discussion with some interest and
being singularly unsurprised about the results. I am speaking way out of
my area of competence (if I have one) and from memory. I should really
check this but don't know where to look. If I am wrong, I am sure someone
will tell me anyway.

As I recall it, the world's epicentre for blood group O is Scandinavia.
Thus people with an ancestry which is Northern European tend to have this
group. Blood group A is (as far as Europe is concerned) more
Mediterranean. Thus, in Southern England group A (as in my case)
predominates but in the North East of England with its predominantly
Scandinavian ancestry, group O predominates.

I imagine that Wheat would be difficult to cultivate in Northern European
climes and so the populace ate rye and oats as their staple diets whereas
the Southern Europeans ate more wheat. Of course, Ireland (along with
Scandinavia (I think) is the world's epicentre for Coeliac type disorders
but I have no idea what blood group predominates. There is a big Danish
contribution around the Dublin area though.

I can't help thinking that the co-incidence of blood group O with Coeliac
conditions is just that: a coincidence rather than one being causative
of the other. These epicentres correspond with what were historically non
wheat eating areas rather than the blood groups.

As some of you know, our main research area is autism and the
possible role of gluten and casein in its causation. We always check out
the ethnic and geographical ancestral histories for this very reason. We
have not asked for blood groups but perhaps we should.

I may have got this wrong and if so I hope that someone will correct me
and stop me from saying it again!!

Paul Shattock (A+)