My father is 100% Irish blood (He is "Black Irish"). Both of my paternal grandparents had venous insufficiency in their legs, and the concommitant venous ulcers - known to have high iron depositions (I am starting to get that too - at 48). My maternal grandfather was English - derived from Belgium, and likely of Celtic ancestry (red hair and fair skin) - in fact, I have tentatively traced that line back to the Assyrians (who were red-headed). My maternal grandmother's family was in England since before 1066 (her family is one of 12 traceable to the Domesday Book.)
Interesting reading is found if you look up Michael Tsarion (vids on Youtube too). He purports that the Celts/Druids went to Egypt (from Ireland) after the Atlantis thing, and came back through Europe to Ireland later.
Interestingly, Egypt has a slightly higher proportion (per capita) than Canada. http://www.wrongdiagnosis.com/m/multiple_sclerosis/stats-country.htm
Even stranger, Guatemala has an almost even rate of incidence with Canada. There are some that say the Mayans also had a Celtic/Druidic influence...
This is becoming tangential, and potentially controversial, but it is interesting none-the-less.