What is Alexander Disease?
Alexander disease 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. Alexander disease is a
progressive and usually fatal disease. 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
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 excessive vomiting, difficulty swallowing and speaking,
poor coordination, and loss of motor control. 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 disease occurs in both males and
females, and there are no ethnic, racial, geographic, or cultural/economic
differences in its distribution.
Is there any treatment?
There is no cure for Alexander disease, nor is there a standard course of
treatment. Treatment of Alexander disease is symptomatic and supportive.
What is the prognosis?
The prognosis for individuals with Alexander disease is generally poor. 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.
What research is being done?
Recent discoveries show that most individuals (approximately 90 percent) with
Alexander disease have a mutation in the gene that makes glial fibrillary acidic
protein (GFAP). GFAP is found in Rosenthal fibers; however it is still unclear
how the mutation causes the disease. Most of the mutations occur without any
known cause and are not inherited from parents. However, there are some people
with Alexander disease who do not have the GFAP mutation, which leads
researchers to believe that there may be other genetic or perhaps even
non-genetic causes of Alexander disease. Current research is aimed at
identifying additional mutations in GFAP that may be responsible for Alexander
disease, understanding the mechanisms by which the mutations cause disease, and
developing better mouse models for the disorder that could ultimately be used
for testing treatments. At present, there is no exact animal model for the
disease; however, mice have been engineered to produce the same mutant forms of
GFAP found in individuals with Alexander disease. These mice form Rosenthal
fibers and have a predisposition for seizures, but do not yet mimic all features
of the human disease.
Organizations
National Organization for Rare Disorders (NORD)
P.O. Box 1968
(55 Kenosia Avenue)
Danbury, CT 06813-1968
orphan@rarediseases.org
www.rarediseases.org
Tel: 203.744.0100 Voice Mail 800.999.NORD (6673)
Fax: 203.798.2291
United Leukodystrophy Foundation
2304 Highland Drive
Sycamore, IL 60178
office@ulf.org
www.ulf.org
Tel: 815.895.3211 800.728.5483
Fax: 815.895.2432
Source: National Institutes of Health; National Institute of
Neurological Disorders and Stroke
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 11/20/2007...#6027
