Rare leukoencephalopathy with infantile-onset accumulation of Rosenthal fibers in the subpial, periventricular, and subependymal zones of the brain. Rosenthal fibers are glial fibrillary acidic protein aggregates found in astrocytes. Juvenile- and adult-onset types show progressive atrophy of the lower brainstem instead. De novo mutations in the GFAP gene are associated with the disease with propensity for paternal inheritance.