ADAR and Aicardi-Goutieres syndrome: Mutations in the gene coding the RNA editing enzyme ADAR1 [1, 2], together with six other genes [3–5], have been linked to Aicardi–Goutières syndrome (AGS), an infant or juvenile-onset neurodegenerative disease often leading to severe brain injury manifested by progressive cognitive and intellectual regression, spasticity, dystonia, and motor disability [3, 6, 7].