Mutations in the RNA helicase domains of RIG-I and MDA5 were found in patients with systemic lupus erythematosus (SLE), Aicardi-Goutieres syndrome (AGS), and Singleton-Merten syndrome (SMS), all of which exhibit a type I IFN signature (164–169). This evidence concerns the gene IFIH1 and Aicardi-Goutieres syndrome.