Aicardi-Goutières (AGS) is a rare immune dysregulated disease due to mutations in TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, ADAR1, or IFIH1. Clinical features include basal ganglia calcifications, white matter abnormalities, and cerebral atrophy. The gene discussed is TREX1; the disease is Cerebral atrophy.