Alexander disease is a slowly progressing and fatal neurodegenerative disease. It is one of a group of neurological conditions known as the leukodystrophies, disorders that are the result of abnormalities in myelin, the “white matter” that protects nerve fibers in the brain.
The destruction of white matter is accompanied by the formation of Rosenthal fibers, which are abnormal clumps of protein that accumulate in non-neuronal cells of the brain called astrocytes. Rosenthal fibers are sometimes found in other disorders, but not in the same amount or area of the brain that are featured in Alexander disease.
The disease occurs in both males and females, and there are no ethnic, racial, geographic, or cultural/economic differences in its distribution.
It results from a genetic mutation. The mutation is not carried by the parents, rather the mutation occurs in the parental gametes (egg or sperm) that then develop into a child with Alexander disease.
The infantile form is the most common type of Alexander disease. It has an onset during the first two years of life. Usually there are both mental and physical developmental delays, followed by the loss of developmental milestones, an abnormal increase in head size, and seizures.
The juvenile form of Alexander disease is less common and has an onset between the ages of two and thirteen. These children may have:
Adult-onset forms of Alexander disease are rare, but have been reported. The symptoms sometimes mimic those of Parkinson’s disease or multiple sclerosis.
The prognosis for individuals with Alexander disease is generally poor. With early onset, death usually occurs within 10 years after the onset of symptoms. Usually, the later the disease occurs, the slower its course is. Most children with the infantile form do not survive past the age of 6. Juvenile and adult onset forms of the disorder have a slower, more lengthy course.
There is no cure for Alexander disease, nor is there a standard course of treatment. Treatment of Alexander disease is symptomatic and supportive.