Alexander Disease, Rosenthal Fiber Encephalopathy

In humans, Alexander Disease is a rare and devastating childhood brain disorder. Alexander disease is in a family of disorders called leukodystrophies in which abnormalities arise in the myelin sheath, a protective insulation that covers nerves. It often strikes infants before their first year of age and causes catastrophic damage throughout the nervous system. Most children do not survive past age 6. Mutations in a gene called GFAP - or glial fibrillary acidic protein - are associated with nearly all cases of Alexander disease. Messing said the mutation triggers production of an abnormal protein, which causes a buildup of fibers that damage the nervous system. ¹

Signs of Alexander Disease

Individuals typically have progressive retardation with loss of developmental milestones, enlarged skull and frontal bossing, seizures, poor movement coordination, gradual loss of intellectual function, seizures, breathing problems and hydrocephalus.

Diagnosis & Management of Alexander Disease

Diagnosis of Alexander disease is based on MRI findings. No specific therapy is currently available for Alexander disease. Treatment is supportive and includes attention to general care and nutritional requirements; antibiotic treatment for intercurrent infection; antiepileptic drugs (AEDs) for seizure control; and assessment for learning disabilities and cognitive impairment.

Alexander disease is inherited in an autosomal dominant manner. The risk to inherit the disease depends upon the genetic status of the parents. If a parent is affected or has a mutation in the GFAP gene, the risk of inheriting the GFAP mutation is 50%.

In dogs, the disease has been described in Bernese Mountain Dog, Scottish Terrier (Rosenthal Fiber Encephalopathy resembling Alexander's disease) and other breeds.²

References
1. Genetic Basis Of Alexander Disease Discovered. ScienceDaily, Jan. 3, 2001
2. N, Marcaccini A, Espino L, Bermudez R, Nieto JM, Lopez-Pena M. Rosenthal fiber encephalopathy in a dog resembling Alexander disease in humans.Aleman. Vet Pathol. 2006 Nov;43(6):1025-8.