[Aicardi-Goutieres syndrome: a family case due to alteration of the RNASEH2B gene].

Introduction: Aicardi-Goutieres syndrome is a progressive encephalopathy with onset in the first year of life that conditions psychomotor retardation, microcephaly and pyramidal dysfunction. It has a prevalence of 1-5 in 10,000 newly live births. Most cases have autosomal recessive transmission, due to alteration in seven genes involved in the metabolism of interferon, which causes an increase in its levels in the blood and cerebrospinal fluid, and affects the brain (leukodystrophy, corticosubcortical atrophy, calcifications in the basal ganglia…), the skin and the immune system.