Alexander disease is a rare, progressive neurological disorder caused by mutations in the GFAP gene. These changes affect astrocytes, cells that help support and protect the brain and spinal cord. The condition can begin in infancy, childhood, or adulthood, and its course varies from person to person. For loved ones and caregivers, this can mean adapting to changing support needs and navigating uncertainty together.

How many people are affected? Approximately every 1 in 1-3 million people. MedlinePlus cites about 500 reported cases since the disease was first described in 1949. This historical figure is not a count of people living with AxD today.

What are the symptoms?  People affected by Alexander Disease may experience developmental delays, seizures, muscle stiffness, an enlarged head, difficulties with balance, coordination, speech, and swallowing. Not everyone experiences every symptom.

Are there treatments? In September 2026, the U.S. FDA approved Zanvastro (zilganersen) for children and adults with Alexander disease, the first treatment to directly target the protein buildup that drives the disease. Supportive care can include medicines for seizures and muscle stiffness, physical and occupational therapy, speech therapy, and nutritional support.