TREX1 and Aicardi-Goutières syndrome: Aicardi-Goutieres syndrome is classified as a monogenic interferon disease resulting from an aberrant mechanism involving intracellular nucleic acid sensing mediated by TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, ADAR1 or IFIH1 [38].