FIG. 1.
Numbers and percentages of families with Aicardi–Goutières syndrome (AGS) with mutations in TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, ADAR and IFIH1. D: denotes dominant mutation. One child with a neurological phenotype and a single heterozygous mutation in TREX1, and three children with single heterozygous mutations in RNASEH2B were also identified. In addition, four families demonstrating autosomal dominant segregation of familial chilblain lupus (FCL) with mutations in either TREX1 (two families) or SAMHD1 (one family) were ascertained. Mutations in RNASEH2B and TREX1 represent more than half of our cohort. Considering their relatively recent identification, it is possible that the proportion of patients with mutations in ADAR and IFIH1 may increase.