What causes a sensitivity to gluten?

In my opinion, gluten sensitivity is caused by our genetic makeup, combined with the increased amounts of gluten in our wheat. Wheat was introduced into Europe during the Middle Ages, and 30 percent of people of European descent carry the gene for celiac disease (HLA DQ2 or HLA DQ8), which increases susceptibility to health problems from eating gluten. American strains of wheat have a much higher gluten content (which is needed to make light, fluffy Wonder Bread and giant bagels) than those traditionally found in Europe. This super-gluten was recently introduced into our agricultural food supply and now has "infected" nearly all wheat strains in America.