Based on the presence of premature CNS basal ganglia mineralisation reminiscent of that seen in classic type-I interferonopathies including AGS, we were interested in assessing signal transducer and activator of transcription (STAT1) phosphorylation and expression of interferon-regulated genes.21 Immunoblotting for phospho-STAT1 in patient fibroblasts and in 293 T cells transfected with WT and mutant constructs revealed that ROSAH-associated mutations result in constitutive STAT1 activation (figure 6A, B). This evidence concerns the gene STAT1 and Aicardi-Goutieres syndrome.