This study will try to identify mutations in the genes responsible for primary immunodeficiency disorders (inherited diseases of the immune system) and evaluate the course of these diseases in patients over time to learn more about the medical problems they cause. The immune system is composed of various cells (e.g., T and B cells and phagocytes) and other substances (complement system) that protect the body from infections and cancer. Abnormalities in the gene(s) responsible for the function of these components can lead to serious infections and other immune problems.