ADAR and Aicardi-Goutieres syndrome: Mutations in seven human genes have been identified in AGS patients: TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, ADAR1 and IFIH1, all being nucleic acid-catabolizing proteins that participate in pathways for sensing and/or clearing away foreign and self-derived nucleic acids17.