SAMHD1 and Cerebral atrophy: Aicardi-Goutières (AGS) is a rare immune dysregulated disease due to mutations in TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, ADAR1 or IFIH1, characterized by encephalopathy, dystonia, basal ganglia calcifications, white matter abnormalities, and cerebral atrophy [1, 2].