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Aicardi–Goutières syndrome (AGS), which is completely distinct from the similarly named Aicardi syndrome, is a rare, usually early onset childhood, inflammatory disorder most typically affecting the brain and the skin (neurodevelopmental disorder). The majority of affected individuals experience significant intellectual and physical problems, although this is not always the case. The clinical features of AGS can mimic those of ''in utero'' acquired infection, and some characteristics of the condition also overlap with the autoimmune disease systemic lupus erythematosus (SLE). Following an original description of eight cases in 1984,〔 the condition was first referred to as 'Aicardi–Goutières syndrome' (AGS) in 1992, and the first international meeting on AGS was held in Pavia, Italy, in 2001. AGS can occur due to mutations in any one of a number of different genes, of which seven have been identified to date, namely: TREX1, RNASEH2A, RNASEH2B, RNASEH2C (which together encode for the Ribonuclease H2 enzyme complex), SAMHD1, ADAR1, and IFIH1 (coding for MDA5). This neurological disease occurs in all populations worldwide, although it is almost certainly under-diagnosed. To date (2014) at least 400 cases of AGS are known. == History == In 1984, Jean Aicardi and Francoise Goutières described eight children from five families presenting with a severe early onset encephalopathy, which was characterized by calcification of the basal ganglia, abnormalities of the cerebral white matter and diffuse brain atrophy.〔 An excess of white cells, chiefly lymphocytes, was found in the cerebrospinal fluid (CSF), thus indicating an inflammatory condition. During the first year of life, these children developed microcephaly, spasticity and dystonia. Some of the parents of the children were genetically related to each other, and the children were both male and female, which suggested that the disease was inherited as an autosomal recessive genetic trait. In 1988, Pierre Lebon and his colleagues identified the additional feature of raised levels of interferon-alpha in patient CSF in the absence of infection. This observation supported the suggestion that AGS was an inflammatory disease, as did the later finding of increased levels of the inflammatory marker neopterin in CSF, and the demonstration that more than 90% of individuals with a genetic diagnosis of AGS, tested at any age, demonstrate an upregulation of interferon-induced gene transcripts - a so-called interferon signature. All cases of Cree encephalitis (an early-onset progressive encephalopathy in a Cree Indian community in Canada), and many cases previously described as pseudo-TORCH syndrome, (toxoplasmosis, rubella, cytomegalovirus, and herpes simplex virus), initially considered to be separate disorders, were later found to be the same as AGS (although other causes of, genetically distinct, ‘pseudo-TORCH’ phenotypes exist). 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Aicardi–Goutières syndrome」の詳細全文を読む スポンサード リンク
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