Endosomal signaling disorders: a new category for immune dysregulation.

Disorders involving endosomal signaling pathways are gaining attention due to their roles in immune regulation. This review proposes a new disease category, endosomal signaling disorders (ESDs), to describe disorders caused by dysfunction of endosomal molecules. Dysregulated endosomal signaling leads to hyperactivation of immune responses, contributing to immune dysregulation disorders such as systemic lupus erythematosus and systemic autoinflammatory disorders. The identification of pathogenic variants in endosomal genes such as TLR3, TLR7, TLR8, UNC93B1, and PLD4 emphasizes the importance of endosomal dysfunction in the pathogenesis of immune dysregulation disorders. Categorizing these diseases as ESDs can help better diagnose and treat these complex conditions, paving the way for targeted therapies and improved patient outcomes.