Neuromyelitis optica in a child with Aicardi-GoutiÈres syndrome

Aicardi-Goutières syndrome (AGS) is a monogenic inflammatory disorder typically presenting in infancy as a progressive encephalopathy demonstrating phenotypic overlap in some cases with both congenital infection and systemic lupus erythematosus (SLE), with mutations in 7 genes identified. All forms are associated with a perturbation of type I interferon metabolism,1 with a defect in the removal, or sensing, of endogenously produced nucleic acid species that activate the immune system.1 Recently, immunoglobulin G staining of astrocytes in brain sections of 3 deceased patients with AGS were reported,2 but no specific antigen was identified and the staining patterns were not typical for neuromyelitis optica (NMO). We describe a girl with a heterozygous mutation in IFIH1 who developed NMO with aquaporin-4 antibodies (AQP4-Ab) who clearly responded to immunotherapy.