Summary

Inborn errors of immunity (IEI), formerly referred to as primary immunodeficiencies, is a growing spectrum of over 550 genetically defined disorders of the immune system. As our understanding of the mechanisms of these disorders grows, immune dysregulation syndromes, autoimmunity, malignancy, bone marrow failure with immunodeficiency, and phenocopies are recognized as part of the clinical spectrum of IEI. Early recognition and accurate classification are critical as many IEI conditions have specific therapeutic implications, including targeted immune modulation, immunoglobulin replacement therapy, hematopoietic stem cell transplantation, and gene therapy. In this review, we present recent changes in classification, updated laboratory workup strategies, and therapeutic advances.