TREX1 and Aicardi-Goutieres syndrome: In the last decade, AGS has been classified as the first monogenic type I interferonopathy, displaying pathogenic mutations either in genes associated with defective disposal of nucleic acids (TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, ADAR) or with altered control of the IFN cascade (IFIH1) [41].