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.
The life expectancy of a patient with Alexander Disease depends on the onset of the condition. Children with infantile Alexander Disease may not live beyond one to two years of life and even if they do, they can go up to maximum of 10 years. Children with juvenile form of Alexander Disease tend to live up to middle age after the diagnosis of Alexander Disease.
The symptoms of Alexander disease can vary. They’re largely dependent on the age of onset. Symptoms can include:
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.
If Alexander Disease is suspected based on the signs and symptoms shown by the patient, a simple genetic testing is enough to confirm Alexander Disease as the defective gene causing this condition is well known and can be easily identified on genetic testing and can confirm the diagnosis of Alexander Disease.
The treatment for Alexander Disease is basically symptomatic and supportive. Certain conditions like seizures and hydrocephaly can be treated. Seizures can be controlled with antiepileptic medications while hydrocephaly can be treated with surgery to drain water from the brain and thus relieve the pressure put on the brain by the water accumulated inside it. On an experimental basis, bone marrow transplantation has been tried as a treatment for Alexander Disease but it has not been found to be much successful.
Because the genetic defect in Alexander disease is known, genetic testing on a blood sample can be used to diagnose most cases of Alexander disease. There is no medication for Alexander disease. Treatment, which is symptomatic and supportive, primarily consists of attention to general care and nutritional needs, antibiotic therapy for infections, and management of associated complications such as anti-epileptic drug therapy for seizures. A suggestive diagnosis can also be made from the clinical symptoms, including enlarged head size, combined with radiological studies and negative tests for other leukodystrophies. Surgical interventions, including placement of a feeding tube and/or shunting for hydrocephalus, may also be required. Orthopedic surgery for scoliosis has been reported in a case of Alexander disease.