We now know that the Irish have a higher percentage of people with celiac disease than the general population. Also the Scandinavians. A person can have gluten-sensitivity that is not "celiac," also. Both are potentially serious. A large list of symptoms can relate to this, many not gastrointestinal, including any auto-immune disease (often thyroid & adrenal), psychological (anxiety, depression, bipolar, schizophrenia), anemia, bone loss,  eczema, psoriasis, hives, inability to digest dairy, etc. The best lab for determining either type of sensitivity is via stool test at www.enterolab.com , run by a brilliant gastroenterologist, Kenneth Fine MD. The person orders their kit directly online, and the results tell you if one or both parents contributed the genes, and if the genes were for celiac or non-celiac gluten sensitivity. Also reported are 2 immune markers for degree of immune reactivity, and "fecal fat" which is used as a marker for degree of villi damage (fingers on intestine that absorb nutrients). A free dairy immune marker is added to the complete panel. The test is pricey but life-changing , if positive. I'm a board certified nutrition consultant, so work with this frequently. Some good books to read are Life After Bread by Eydi Bauer DC & The Gluten Syndrome: Is Wheat Causing You Harm? by Rodney Ford MD. An amazing baking cookbook is "Gluten-Free Baking with the Culinary Institute of America" by Richard Coppedge Jr. with every bread you ever loved!