Alexander disease is a rare, genetic, degenerative disorder of the nervous system. It is one of a group of genetic disorders called the leukodystrophies that affect growth of the myelin sheath on nerve fibers in the brain. The myelin sheath is the fatty covering that acts as an insulator.
A rare neurodegenerative disorder characterized by early onset dementia or encephalopathy and muscular spasticity. It usually results from a mutation in the gene that codes for glial fibrillary acidic protein (GFAP). Brain specimens from affected patients show the accumulation of abnormal inclusion bodies within astrocytes.