Severe type 1 interferonopathy due to germline STAT2 gain-of-function

The transcription factor STAT2 is essential for transcriptional activation downstream of the receptors for the innate IFNs -a/ß (IFNAR) and -gamma (IFNLR). STAT2 is activated by tyrosine phosphorylation, associating with STAT1 and IRF9 to form the Interferon-Stimulated Gene Factor 3 (ISGF3) to effect gene transcription. Loss-of-function variants in STAT2 increase susceptibility to viral disease. Here a transcriptome study is reported on an individual with severe early-onset neuroinflammatory disease and an elevated IFN signature. The individual had a homozygous missense variant in STAT2 and symptoms consistent with a gain-of-function effect.