Alexander disease is a devastating brain disease that almost nobody has heard of— unless someone in the family is afflicted with it. Alexander disease strikes young or old, and in children, it destroys white matter in the front of the brain. Many patients, especially those with early onset, have significant intellectual disabilities.
Regardless of the age when it begins, Alexander disease is always fatal. It typically results from mutations in a gene known as GFAP (glial fibrillary acidic protein), leading to the formation of fibrous clumps of protein inside brain cells called astrocytes.
Classically, astrocytes and other glial cells were considered “helpers” that nourish and protect the neurons that do the actual communication. But in recent years, it’s become clear that glial cells are much more than passive bystanders, and may be active culprits in many neurological diseases.