Celiac disease (CD) is a complex disease caused by eating gluten, a protein contained in wheat, rye, and barley. It is well known that many factors contribute to the development of CD, including the genes that you have and the foods that you eat. In the CDGEMM study, we will consider as many of these factors as possible and study how they each contribute to disease development. If the investigators find that any one factor, or combination of factors, increases the risk of developing CD, we will be able to apply this information and help prevent or detect disease in high-risk children in the future.