Alexander Disease type 1


Usually sporadic Disease occurs because of a new mutation

Less commonly Autosomal Dominant Inheritance from one parent will result in the disease

Age range at onset:

Under 4 years old

Specialists you may see:


Type 1 Alexander Disease is the most common form and presents in the first 2 years of life.

Rarely it may present in the neonatal period. Symptoms typically include encephalopathy (brain disease, damage or malfunction), an enlarged brain and head, seizures, failure to thrive, stiffness in the arms and legs, delayed learning and physical development. Affected individuals have a very reduced life span ranging from several months to several years.


A mutation in the GFAP (Glial Fibrillary Acidic Protein) gene is the cause of Alexander Disease. Normally GFAP is important for supporting the myelin (white matter) that surrounds the nerve fibres in the brain. In Alexander Disease there is an overproduction of abnormal GFAP which results in damage of normal myelin formation and maintenance and impairment of brain function.

In most people with Alexander Disease the mutation in the GFAP gene occurs at the time of conception (this is called de novo) and is not inherited from a parent. However occasionally Type 2 Alexander Disease is caused by a GFAP mutation that has been inherited from one of the parents