Since the RNASEH2B is the most commonly altered gene in AGS, in this work, the AGS group was composed of sixteen RNASEH2B-mutated patients, twelve of whom carry the p.A177T mutation with both mild and severe phenotypes, one RNASEH2A, TREX1 and IFIH1-mutated patients, four patients carrying mutations in SAMHD1 gene and two ADAR1-mutated patients. This evidence concerns the gene TREX1 and Aicardi-Goutieres syndrome.