In the severe neuroinflammatory disorder Aicardi-Goutières syndrome, more than 50% of total AGS patients have biallelic mutations in one of the three genes encoding RNase H2: 5% for RNASEH2A, 36% for RNASEH2B, and 12% for RNASEH2C [26]. The gene discussed is RNASEH2A; the disease is Aicardi-Goutieres syndrome.