TREX1 and Aicardi-Goutières syndrome: For example, following the discovery of mutations in the TREX1 gene causing the type I interferonopathy Aicardi–Goutières syndrome, TREX1 variants were identified in up to 0.5–2% of patients with SLE (Lee-Kirsch et al., 2007; Namjou et al., 2011).