Celiac /Coeliac disease – cause
The following extract is one of the most concise "cause" definitions of celiac disease.
The exact cause of celiac disease is not known; however, inheriting or developing certain irregular genes increases your susceptibility. You are more likely to have these abnormal genes and develop celiac disease if you have a first-degree relative (mother, father, brother, sister, son, or daughter) with the condition. In some genetically predisposed people, environmental factors, such as bacteria, viruses, or surgery, may cause changes in the small intestine; then, eating gluten can trigger an irregular immune system response, resulting in celiac disease. The principal cause of the disorder is an immunologic reaction to components of certain dietary glutens. This is a cell-mediated reaction, not a typical IgE type allergy. The targets of the immunologic response are gliadin, hordein, and secalin, proteins contained in the gluten component of wheat, barley, and rye. Traditionally, oats have been included in the list as well, but some recent studies have brought into question whether this is necessary. Corn (maize), sorghum, and rice are considered safe for a patient to consume. They do contain types of gluten that do not trigger the disease.
Some people have an allergy to gluten and must go on a gluten-free diet. In their case, the gluten damages the mucosa of the small intestine in a way that a normal digestion becomes impossible. After avoiding gluten completely, the intestine will return to functioning normally. People with celiac disease have a hereditary, genetic predisposition to autoimmune reaction to gluten in their digestive system and must avoid it entirely. People with autism and autistic spectrum disorders, like Asperger's syndrome, may be sensitive to gluten and casein (a protein in milk). See more at gluten-free, casein-free diet. Another condition which may cause one to follow a gluten-free diet is dermatitis herpetiformis. Gluten is found in most cereals (e.g., wheat, rye and barley) and their end products. No gluten is contained in rice, soybean (soya), maize (corn), buckwheat, and sunflower seeds, for example. Oats and Teffs do not contain gluten, but are usually milled on the same equipment as other grains that do, and so are commonly contaminated.