RNASEH2A and Aicardi-Goutieres syndrome: Up to now, nine genes (TREX1, RNASEH2B, RNASEH2A, RNASEH2C, ADAR1, SAMHD1, IFIH1, LSM11 and RNU7) associated with AGS phenotype with an autosomal recessive or dominant inheritance have been discovered, which are all involved in nucleic acids (NAs) metabolism or signaling [2,3,4].