Multisystem autoimmune disease due to IKAROS gain of function

An autoimmune disease caused by a loss-of-function variation in the IKZF1/IKAROSgene. Leukocytes of patients exhibited specific defects including impaired IL-2 production by T cells, T helper (TH) skewing toward TH2, low numbers of regulatory T cells (Treg), eosinophilia, and abnormal PC proliferation.