Keeping up with Recent Developments in Immunodeficiency.

Inborn Errors of Immunity are a rapidly expanding group of monogenetic disorders affecting the immune system. Advancements in genetic testing and functional validation studies have accelerated the pace of IEI gene discovery and mechanism of disease, particularly in the past five years. To keep up with this rapid expansion, the International Union of Immunological Societies (IUIS) Expert Committee has periodically, since 1999, released updated IEI classifications with corresponding genotypic and phenotypic catalogues with its most recent update in 2022.1-5 Now there are over 485 monogenetic disorders of the immune system described among 10 main groups of classification. This article reviews recent clinical developments in IEI, including a closer look at some of the more recently described IEI disorders. In particular we highlight a few disorders with the following clinical phenotypes of IEI: severe atopy, immunodeficiency with immune dysregulation, immune dysregulation with lymphoproliferation, autoinflammation, and innate phenotype. To aid the clinician, we also provide a diagnostic approach to use when there is suspicion of IEI and a discussion of management and treatment.