JAK Inhibitor Treatment in AGS

Inclusion Criteria: * Clinical or molecular identification of Aicardi Goutières Syndrome including the following features * Cerebrospinal fluid (CSF) or blood markers suggesting elevations of markers of interferon activation including CSF pleocytosis, elevation of interferon, and/or neopterin and tetrahydrobiopterin elevations * Evidence of neurologic disease on neuroimaging including intracranial calcifications and or a leukoencephalopathy * Clinical features of disease including features such as microcephaly, subacute encephalopathy, myopathy, spastic diplegia, skin involvement, autoimmune hepatitis, hematologic abnormalities * OR have documented mutations felt to be pathogenic in an AGS associated gene. * Are ≥1 month of age. * Are ≥4.5 kg in body weight. * Females after menarche must have a negative urine/serum pregnancy test and must use an acceptable method of contraception, including abstinence, a barrier method (diaphragm or condom), Depo-Provera, or an oral contraceptive, for the duration of the study. * Parental/guardian permission (informed consent). Exclusion Criteria: * Are pregnant or nursing at the time of entry or unable to use contraception as detailed below * Are females of childbearing potential (women \>12 or who have had at least one menstrual period regardless of age) who are sexually active and who do not agree to use 2 forms of highly effective methods of birth control (see below) or remain abstinent during the study and for at least 28 …