Ping.
I saw the claim not long ago that the problem was first diagnosed in the Roman period.
Recalling that the Greeks went to Denmark in search of amber, and then sailed up the Gulf of Bothnia to see the Sa'ami ski, I wouldn't be surprised to find that they brought back at least one individual with the genes for gluten intolerance.
Give that 2 or 3 generations to work itself out in a small village, and next thing you know you'd have lots and lots of cousins producing lots and lots of other cousins with the same autosomal recessive!
Thank goodness they didn't demand the guy teach them Curling ~ or, maybe they did ~ Bocci looks a lot like Curling.