Healthy normal volunteers between 18 and 65 years of age and patients with chronic granulomatous disease (CGD), X-linked severe combined immune deficiency (X-SCID), leukocyte adhesion deficiency (LAD), interferon gamma receptor deficiency (IGR-deficiency) or other inherited diseases affecting precursor blood cells-bone marrow cells that generate blood cells-may be eligible for this study. Patients who have had repeated severe infections possibly due to an inherited blood cell abnormality may also participate. Candidates will be screened with a medical history, physical examination and blood tests.