Aicardi–Goutières syndrome (AGS), which is completely distinct from the similarly named Aicardi syndrome, is a rare, usually early onset childhood, inflammatory disorder most typically affecting the brain and the skin (neurodevelopmental disorder). The majority of affected individuals experience significant intellectual and physical problems, although this is not always the case. The clinical features of AGS can mimic those of in utero acquired infection, and some characteristics of the condition also overlap with the autoimmune disease systemic lupus erythematosus (SLE). Following an original description of eight cases in 1984, the condition was first referred to as 'Aicardi–Goutières syndrome' (AGS) in 1992, and the first international meeting on AGS was held in Pavia, Italy, in 2001.

AGS can occur due to mutations in any one of a number of different genes, of which seven have been identified to date, namely: TREX1, RNASEH2A, RNASEH2B, RNASEH2C (which together encode the Ribonuclease H2 enzyme complex), SAMHD1, ADAR1, and IFIH1 (coding for MDA5). This neurological disease occurs in all populations worldwide, although it is almost certainly under-diagnosed. To date (2014) at least 400 cases of AGS are known.