About alexander disease

What is alexander disease?

Alexander disease is named after the physician who first described the condition in 1949 (WS Alexander). It is an extremely rare, usually progressive and fatal, neurological disorder. Initially it was detected most often during infancy or early childhood, but as better diagnostic tools have become available has been found to occur with similar frequency at all stages of life. Alexander disease has historically been included among the leukodystrophies--diseases of the white matter of the brain. These diseases affect the fatty material (myelin) that forms an insulating wrapping (sheath) around certain nerve fibers (axons). Myelin enables the efficient transmission of nerve impulses and provides the "whitish" appearance of the so-called white matter of the brain. There is a marked deficit in myelin formation in most early onset cases of Alexander disease, and sometimes in later onset cases, particularly in the front (frontal lobes) of the brain's two hemispheres (cerebrum). However, white matter defects are sometimes not observed in later onset cases. Instead, the unifying feature among all Alexander disease cases is the presence of abnormal protein aggregates known as "Rosenthal fibers" throughout certain regions of the brain and spinal cord (central nervous system [CNS]). These aggregates occur in astrocytes, a particular cell type in the CNS that helps maintain a normal CNS environment. Accordingly, it is more appropriate to consider Alexander disease a disease of astrocytes (an astrogliopathy) than a white matter disease (leukodystrophy).

What are the symptoms for alexander disease?

The symptoms of Alexander disease can vary. They’re largely dependent on the age of onset. Symptoms can include:

  • spasms
  • learning disability
  • feeding problems
  • enlarged head size
  • hydrocephalus (fluid in the brain)
  • enlarged brain
  • delayed development
  • seizures
  • failure to thrive
  • impaired mobility
  • speech problems
  • mental regression
  • difficulty swallowing
  • an inability to cough
  • sleep disturbances

The severity of symptoms can also vary greatly. In general, the earlier the onset of the disease, the more severe the symptoms and the more quickly the condition progresses.

Alexander disease is fatal. Many infants with the condition don’t survive past the first year of life. Children who develop the disease between the ages of 4 and 10 tend to decline gradually. They can live for several years following diagnosis, and some may live into middle age.

What are the causes for alexander disease?

Alexander disease is caused by a defect in the glial fibrillary acidic protein (GFAP) gene in around 90 percent of cases, according to the Genetic and Rare Diseases Information Center. The GFAP gene is involved in the development of cell structure, but more research is needed to understand GFAP’s specific role within health and disease. It’s unknown what causes Alexander disease in the small number of other cases.

The gene defect doesn’t appear to be hereditary. Instead, it seems to occur at random. Some cases of familial Alexander disease have been reported. However, this is more often in the adult form.

According to the National Institutes of Health, only about 500 cases of Alexander disease have been reported since 1949.

What are the treatments for alexander disease?

Currently, there’s no cure for Alexander disease. Only the symptoms can be treated. Since there’s no specific therapy available for the condition, caregivers aim to manage the disease supportively. Particular attention is given to:

  • overall care
  • occupational and physical therapy
  • nutritional needs
  • speech therapy
  • antibiotics for any infections developed
  • antiepileptic drugs to control seizures

Hydrocephalus can be partially relieved by surgery. The surgery involves inserting a shunt to drain away some of the fluid in the brain and relieve the pressure on the brain.

What are the risk factors for alexander disease?

Alexander disease has been estimated to occur at a frequency of about 1 in 1 million births. No racial, ethnic, geographic, or sex preference has been observed, nor is any expected given the de novo (new) nature of the mutations responsible for most cases. Although initially diagnosed primarily in young children, it is now being observed with similar frequency at all ages.

Is there a cure/medications for alexander disease?

The outlook for people with Alexander disease is generally quite poor. Outlook largely depends on what age onset occurs. Infants who develop the disease before the age of 2 normally don’t survive past the age of 6. For older children and adults, the disease usually takes a slower course, and symptoms aren’t as severe. In some adult cases of the disease, there can be no symptoms present at all.

If your child has received a diagnosis of Alexander disease, there are organizations that can provide support. The United Leukodystrophy Foundation and Contact not only offer help and support, but can also connect you with other families who have children with the same condition.

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