The primary immunodeficiency disorders

The primary immunodeficiency disorders are clinically heterogeneous diseases, the majority of which arise from inborn errors in immunologically relevant genes. A high index of suspicion is required to reach a diagnosis of primary immunodeficiency, and a timely diagnosis significantly improves patient outcomes. This contribution reviews the relationships between the underlying genetic defects and the associated immunological and clinical phenotypes seen in clinical practice. Diagnostic and therapeutic approaches to primary immunodeficiencies are also discussed.