A recent study of interferon-related gene expression in seven patients with sine causa spastic-dystonic tetraparesis led to the diagnosis of AGS in one patient by the demonstration of a “type 1 interferon signature,” a specific expression pattern of IFN-related genes identified in type 1-interferonopathies (19, 20). This evidence concerns the gene IFNA1 and Aicardi-Goutieres syndrome.