This fact sheet provides information about Alexander disease, a rare disorder of the nervous system caused by the mutation of the GFAP gene.

 

Alexander disease

 Leukodystrophies are a group of disorders that involve the destruction of myelin. Myelin is a fatty covering that is used by the body to insulate nerve fibres and helps to promote rapid transmission of nerve impulses through the nervous system. If there is a problem with the myelin, as is the case in leukodystrophies, nerve impulses can be disrupted, leading to an impairment of the nervous system.

Diagnosis

Diagnosis will depend on the type of leukodystrophy, and often will need a number of specialists to be involved, including neurologists, and geneticists. The diagnostic methods vary between types, some of these include:

* Physical examination

* Blood testing

* Urine testing

* Genetic testing

* MRI

* Nerve conduction testing

Signs and Symptoms

* Vary by disease (see below)

Treatment

No specific therapy is currently available to treat these disorders. Management is generally supportive and includes a multitude of medical participants including physicians, occupational therapists, physiotherapists and many more.

A type specific to section 24 of the NDIS Act

Alexander disease [infantile and neonatal forms]

Alexander disease is a rare disorder of the nervous system caused by a mutation of the GFAP gene. The GFAP gene provides the instructions for the formation of a protein called glial fibrillary acidic protein, which provides support and strength to the cells in the nervous system. Alexander disease is characterised by destruction of the myelin sheath, and abnormal protein deposits known as Rosenthal fibres. Most cases of Alexander disease begin before the age of two.

Frequency

The prevalence of Alexander disease is largely unknown. Since the disease was first described in 1949, only approximately 500 cases have been reported.

Signs and Symptoms

Neonatal

* Occurs in the first month of life

* Severe intellectual disability

* Severe developmental delay

* Build-up of fluid on the brain (hydrocephalus)

* Seizures

* Usually fatal within the first few weeks to years of life

Infantile

* Enlarged head size

* Seizures

* Stiffness of the arms and/or legs

* Intellectual disability

* Developmental delay

* Failure to thrive

* Speech problems

* Usually fatal within the first few years of life

References: 

Alexander Disease (2019). Retrieved from https://ghr.nlm.nih.gov/condition/alexander-disease#genes

Alexander Disease (2019). Retrieved from https://rarediseases.org/rare-diseases/alexander-disease/ 

Alexander Disease (2019). Retrieved from https://rarediseases.info.nih.gov/diseases/5774/alexander-disease

Alexander Disease (2019). Retrieved from https://www.uptodate.com/contents/alexander-disease#H1