The Immune Deficiency Foundation (IDF) is the national patient organization dedicated to improving the diagnosis, treatment and quality of life of persons with primary immunodeficiency diseases through advocacy, education and research. Primary immunodeficiency diseases are a group of relatively rare conditions caused by intrinsic or genetic defects in the immune system. Since 1980, IDF has provided accurate and timely information for the nearly quarter-million Americans who have been diagnosed with a primary immunodeficiency disease. Today, thousands of individuals and families affected by primary immunodeficiency diseases depend on IDF for advocacy, education and empowerment.