Laboratory: normal metabolic and infective screening. An increase in the number of white cells (particularly lymphocytes) in the CSF, and high levels of interferon-alpha activity and neopterin in the CSF are important clues - however, these features are not always present. More recently, a persistent elevation of mRNA levels of interferon-stimulated gene transcripts have been recorded in the peripheral blood of almost all cases of AGS with mutations in TREX1, RNASEH2A, RNASEH2C, SAMHD1, ADAR1 and IFIH1, and in 75% of patients with mutations in RNASEH2B. These results are irrespective of age. Thus, this interferon signature appears to be a very good marker of disease. Neuroradiology: The spectrum of neuroradiological features associated with AGS is broad, but is most typically characterised by the following: :*Cerebral calcifications: Calcifications on CT (computed tomography) are seen as areas of abnormal signal, typically bilateral and located in the basal ganglia, but sometimes also extending into the white matter. Calcifications are usually better detected using CT scans (and can be missed completely on MRI without gradient echo sequences (magnetic resonance imaging)). :*White matter abnormalities: These are found in 75-100% of cases, and are best visualised on MRI. Signal changes can be particularly prominent in frontal and temporal regions. White matter abnormalities sometimes include cystic degeneration. :*Cerebral atrophy: is seen frequently. Genetics: pathogenic mutations in any of the seven genes known to be involved in AGS.
Aicardi–Goutières syndrome
Witteveen–Kolk syndrome
Pork–cat syndrome
Woodhouse–Sakati syndrome
RAPADILINO syndrome
Phidippides cardiomyopathy
Bannayan–Riley–Ruvalcaba syndrome
Galloway Mowat syndrome