Both P1 and P2 demonstrated a mildly elevated ISG score (respectively 3.86 and 3.94) in contrast with a control group of three AGS patients with biallelic mutations in SAMHD1 (7.94), RNASEH2B (10.14), or TREX1 (11.60) (Fig. 3b, Table S5, case descriptions in supplemental data S1). This evidence concerns the gene SAMHD1 and Aicardi-Goutieres syndrome.