Primary Immunodeficiency Diseases (PIDs) refer to a collection of over 400 individually rare genetic disorders where patients have increased infections, autoimmunity, and inflammation. In these disorders there is usually a genetic variant (also called mutation) that is the cause of the immune disorder. The thousands of other variants, which are not the cause of the disease, often go unstudied. We want to study those common variants in patients with PIDs to understand how the common mutations contribute as "modifiers" of the disease. For example, common "background" variants may influence when a PID presents (adulthood or childhood), or how severely they present.
