The Mechanistic Biology of Primary Immunodeficiency Disorders

* INCLUSION CRITERIA: 1. Subjects must meet one of the following 4 criteria: 1. Patients (age 0-90 years) with a clinical diagnosis of a form of PID (either known or unknown). PID is defined by laboratory and/or clinical findings on two or more occasions that are consistent with a defect in innate or adaptive immunity. Specific PIDs are defined by the International Union of Immunological Societies guidelines. These subjects must also be willing to undergo genetic testing and to allow their biospecimens to be modified into iPS cells. Women of childbearing potential, or who are pregnant or lactating, may be eligible. The volume of blood collected for research purposes will be reduced, and no skin biopsies will be performed for research purposes in consideration of their safety. 2. Infants identified at birth with positive newborn screening for SCID and confirmed to have T-cell lymphocytopenia. These subjects must be willing to undergo genetic testing. 3. Biological relatives (age 0-90 years) of a subject who meets criterion 1a or 1b but who do not have a PID themselves. All relatives must be willing to undergo genetic testing. Women of childbearing potential, or who are pregnant or lactating, may be eligible. The volume of blood collected for research purposes will be reduced in consideration of their safety. 4. Healthy volunteers (age 18-75 years) who are not related to another study subject, who do not have a PID, whose weight is greater than 110 pounds, do not have a history of any heart, lung, or kidney disease, or bleeding disorders, do not have a history of viral hepatitis (B or C), and have a negative HIV screening test. 2. All subjects must be willing to allow their samples to be stored for future research. EXCLUSION CRITERIA: 1. Subjects with secondary causes of immunodeficiency are excluded from this study. Secondary causes of immunodeficiency include HIV infection and immunodeficiency that is deemed to be secondary to chronic use of immunosuppressive medications or chemotherapeutic agents. 2. Any condition that, in the opinion of the investigator, contraindicates participation in this study.