This information is provided by the National Institutes of Health (NIH) Genetic and Rare Diseases Information Center (GARD).
Alexander disease is a type of leukodystrophy characterized by the destruction of the myelin sheath (the fatty covering that acts as an insulator around nerve fiber) and abnormal protein deposits known as Rosenthal fibers. Most cases of Alexander disease begin before age 2 years (the infantile form). Symptoms of the infantile form include an enlarged brain and head, seizures, stiffness in the arms and/or legs, intellectual disability, and delayed physical development. Less frequently, onset occurs later in childhood (the juvenile form) or adulthood. Common problems in juvenile and adult forms of Alexander disease include speech abnormalities, swallowing difficulties, and poor coordination. Alexander disease is caused by mutations in the GFAP gene. While this condition is inherited in an autosomal dominant fashion, most cases result from new mutations in the gene.
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