TREX1 and Aicardi-Goutières syndrome: 27 Missense TREX1 variants are also associated with Aicardi-Goutières syndrome,28 a form of pediatric-onset encephalopathy, and familial chilblain lupus.29 Three novel missense variants (p.Gly197Ala, p.Arg229Gly, p.Lys230Asn), 1 novel in-frame deletion, and 1 previously reported frameshift variant were found in 5 individuals (0.5%, 95% CI 0.2%–1.2%).