Thursday, 05 August 2004
Last Updated Sunday, 21 November 2004
What
Alexander Disease is a rare, progressive neurological disorder caused by the destruction of nerve fibers in the brain leading to seizures, spasticity (muscle stiffness) and mental retardation
Who
: Children with Alexander disease are generally first diagnosed in early infancy but there are cases arising in late childhood and early adulthood. Boys are more commonly affected and there is no known ethnic or racial preference. The frequency of this disease in not fully known.
Signs and Symptoms
: Children with Alexander disease usually have the following:
- Failure to grow normally
- Mental and physical retardation
- Macrocephaly (enlarged head)
- Increased muscle stiffness and tone
- Worsening clumsiness
- Loss of normal childhood developmental milestones
- Uncontrolled seizures
Possible Causes
Alexander disease is caused by the destruction of the brain’s white matter or myelin sheaths which are the fatty coverings that act as an insulator around the nerve fibers in the brain. The destruction occurs due to a defect in the production of the protein known as glial fibrillary acidic protein (GFAP). Ninety percent of children with Alexander disease have a defect in the GFAP
gene that more commonly arises spontaneously rather than being inherited from a parent. Children who acquire the inherited form do so by inheriting only 1 defective
gene from either parent.
Diagnosis
Alexander Disease is diagnosed by the combination of clinical symptoms, molecular genetic testing, and brain
biopsy. Many disorders have similar symptoms as Alexander Disease, so genetic testing and brain biopsies are used to confirm the diagnosis. In genetic testing, a
mutation of the GFAP
gene on
chromosome 17 confirms the diagnosis. Prior to this current
DNA based testing method, the diagnosis was made by brain
biopsy and looking for specific protein deposits known as Rosenthal fibers. If the child is having seizures, an MRI (magnetic resonance imaging) scan of the brain may be ordered along with an electroencephalogram (
EEG) to study the brain’s electrical activity.
Treatment
Therapy is provided for the symptoms of the disease, but unfortunately there is no treatment that will stop the onset or progression or cure the condition. Focus of care is assuring adequate nutritional intake for growth, controlling any seizures with medications, and providing antibiotics for any infections. Special education programs in school are important to promote mental and physical abilities and physical therapy at home can help with muscle stiffness.
Prognosis
The prognosis of Alexander Disease varies according to the age of diagnosis, but nevertheless, the prognosis is poor. Most children who are affected in early infancy do not survive beyond early childhood and those who are diagnosed later in childhood have a slower, more prolonged course with survival to the twenties and thirties.
Connect with other parents
In the spirit of community and support, Madisons Foundation offers the unique service of connecting parents of children with rare diseases. If you would like to be connected to other parents of children with this disease,
please fill out this brief form.
Weblinks
National Institute of Neurological Disorders and Stroke
organization for families affected by this disorder.
The Waisman Center
Very reliable information and starting point for this rare disease.
United Leukodystrophy Foundation
National organization centered around building awareness.
Orphanet
Good reference for computer savvy parents.
Google Search for Alexander Disease
References and Sources
Johnston MV (2004). Neurodegenerative Disorders of Childhood. In: Behrman RE, Kliegman RM, Jenson HB (eds) Nelson Textbook of Pediatrics, 17th ed. WB Saunders, p. 2034
Gordon N (2003). Alexander Disease. European Journal of Paediatric Neurology. 7, p. 395-399.
Gorospe JR (2003). Alexander Disease. www.geneclinics.org/profiles/alexander/
Johnson AB (2002). Alexander Disease: a review and the
gene. International Journal of Developmental Neuroscience. 20, p. 391-394.