Immune dysregulation and systemic hyperinflammation syndrome (IMDYSHI) is an autosomal recessive immunologic disorder characterized by systemic hyperinflammation in the absence of an infectious agent or autoimmune trigger. Features include lymphadenopathy, hepatosplenomegaly, recurrent fever, and laboratory evidence of immune dysregulation with abnormal immune cell populations and increased serum levels of inflammatory cytokines. The phenotype is reminiscent of relapsing hemophagocytic lymphohistiocytosis (HLH; see FHL1, 267700) (summary by Tavernier et al., 2019). [from
OMIM]