Patients of any age with abnormal immune function who have recurrent or unusual infections, whose blood tests show evidence of immune dysfunction, or who have GVHD, XSCID, CGD or LAD may be eligible for this study. Patients' parents, siblings, grandparents, children, aunts, uncles and first cousins of any age also may be included. Healthy normal volunteers between 18 and 85 years of age are recruited as controls.