Patients with immune disorders known or suspected to have a genetic basis and their family members may enroll in this study. Eligibility will be determined by a review of the patient s medical records and family medical history. Participants will provide a small blood sample for genetic (DNA) and white blood cell analysis. Gene samples (but not white blood cells) may also be obtained by mouth brushing or skin biopsy. For the mouth brushing, a small brush is rubbed against the inside of the cheeks for 1 minute to wipe off some cells. For the skin biopsy, a small circle of skin (about 1/8 inch) is removed under local anesthetic. Pregnant women may be asked to provide a fetal sample (amniotic fluid cells or chorionic villus sample). All samples will be used for immune or genetic studies of the family s immune disorder.