This study will evaluate the safety and effectiveness of the drug, interferon gamma, in treating leukocyte adhesion deficiency type I (LAD I). Patients with this inherited immune disorder do not have enough proteins called adhesion molecules on their infection-fighting white blood cells, impairing the ability of these cells to get to the site of infection. As a result, patients have recurrent infections of soft tissues, such as the skin, gums and gastrointestinal tract, and poor wound healing. Infants with severe LAD I often die from multiple infections. Interferon gamma may increase the number of adhesion molecules on white blood cells, and thus improve their function.