Human germline biallelic loss-of-function OSMR variants cause severe allergic disease

OSMRβ (Oncostatin M receptor beta), a member of the IL-6 superfamily of cell surface receptors, binds OSM and IL-31 and plays a critical role in human immunity. We identified probands from four kindreds with biallelic damaging variants in OSMR, which encodes OSMRβ. Patients had a unifying phenotype for severe widespread, early-onset atopic dermatitis, peripheral eosinophilia, and elevated serum IgE. Patient OSMRβ variants were not appropriately expressed on the cell surface compared to OSMRβWT. Patient OSMR variants showed significantly reduced OSM-mediated activation of STAT1, STAT3, and STAT5 and distinct transcriptional changes in primary dermal fibroblasts, including loss of interferon and inflammatory signatures. These defects were rescued upon lentiviral transduction of WT-OSMR. Together, these data establish that human germline biallelic loss-of-function OSMR variants cause severe allergic disease. We anticipate that this discovery will facilitate the recognition of additional affected individuals and the full definition of this novel primary atopic disorder.