Affiliation: | (1) INSERM U546, Faculté de la Pitié Salpêtrire, 105 boulevard de lhôpital, 75013 Paris, France;(2) Service de Neurologie Pédiatrique, Hôpital Armand Trousseau, AP-HP, 26 avenue du docteur Arnold Netter, 75012 Paris, France;(3) INSERM UMR 384, Faculté de Médecine, Clermont-Ferrand, France |
Abstract: | Alexander disease (AXD) is the first primary astrocytic disorder. This encephalopathy is caused by dominant mutations in the glial fibrillary acidic protein (GFAP) gene, encoding the main intermediate filament of astrocyte. Pathologically, this neurodegenerative disease is characterised by dystrophic astrocytes containing intermediate filament aggregates associated with myelin abnormalities.More than 20 GFAP mutations have been reported. Many of them cluster in highly conserved regions between several intermediate filaments. Contrary to other intermediate filament-related diseases, AXD seems to be the consequence of a toxic gain of function induced by aggregates. This is supported by the phenotype of mice overexpressing human GFAP. Nevertheless, GFAP null mice display myelin abnormalities and blood-brain barrier dysfunction that are present in AXD.Given the pivotal role of astrocytes in brain physiology, there are many possibilities for astrocytes to dysfunction and to impair the functions of other cells. Physiopathological hypotheses are discussed in the frame of AXD.Received 11 April 2003; received after revision 22 July 2003; accepted 31 July 2003Both authors contributed equally to this work. |