Alexander disease (AxD) is a rare autosomal dominant leukodystrophy with three clinical subtypes: infantile, juvenile and adult. Forms differ by age of symptoms occurrence and the clinical presentation. Although recent data suggest considering only two subtypes: type I (infantile onset with lesions extending to the cerebral hemispheres); type II (adult onset with primary involvement of subtentorial structures). Dominant mutations in the glial fibrillary acidic protein (