Characterization of the Molecular Dysfunctions Occurring in Aicardi-Goutières Syndrome Patients with Mutations in ADAR1

Aicardi-Goutières syndrome(AGS)is a systemic inflamma-tory disorder caused by mutations in any one of the nine different genes,whose deficiency provokes a type I(interferon)IFN response probably central to pathogen-esis.1 ADAR1,one of the genes mutated in AGS(AGS6),encodes for an enzyme that belongs to the ADAR family(ADAR1,ADAR2,and ADAR3)that catalyzes the conversion of adenosine to inosine within double-stranded RNAs(dsRNAs)(RNA editing A-to-I).2,3 Two main isoforms of ADAR1 are expressed in mammals:the full-length p150 that is interferon-inducible and the constitutively expressed shorter isoform p110.