Rare Primary Care News

Disease Profile

Acute necrotizing encephalopathy

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.


US Estimated

Europe Estimated

Age of onset





Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.


Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)

Acute necrotizing encephalitis; ANE


Acute necrotizing encephalopathy (ANE) is a rare disease characterized by brain damage (encephalopathy) that usually follows an acute febrile disease, mostly viral infections.[1]. Most of the reported cases are from previously healthy Japanese and Taiwanese children, but it is now known that the disease may affect anybody in the world. The symptoms of the viral infection (fever, respiratory infection, and gastroenteritis, among others) are followed by seizures, disturbance of consciousness that may rapidly progress to a coma, liver problems, and neurological deficits.[1][2] 

The disease is caused by both environmental factors and genetic factors. Usually, ANE develops secondary to viral infections, among which the influenza A, influenza B, and the human herpes virus 6, are the most common. ANE can be familial or sporadic, but both forms are very similar to each other. Most familial cases are caused by mutations in the RANBP2 gene, and are known as “infection-induced acute encephalopathy 3 (IIAE3)”.[2][3]

Although the clinical course and the prognosis of ANE are diverse, the characteristic that is specific to the disease is the “multifocal symmetric brain lesions affecting the thalami, brain stem, cerebral white matter, and cerebellum” which can be seen on computed tomography (CT) or magnetic resonance imaging (MRI) exams. A picture of the brain may help you better visualize the areas of the brain affected. The best treatment of ANE is still under investigation but may include corticosteroids and anticytokine therapies, including TNFα antagonists.[2] 


Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

    Learn more

    These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

    In-Depth Information

    • PubMed is a searchable database of medical literature and lists journal articles that discuss Acute necrotizing encephalopathy. Click on the link to view a sample search on this topic.


      1. Neilson D. Susceptibility to Infection-Induced Acute Encephalopathy 3. GeneReviews. December 4, 2014; https://www.ncbi.nlm.nih.gov/books/NBK258641/.
      2. Xiujuan Wu, Wei Wu, Wei Pan, Limin Wu, Kangding Liu & Hong-Liang Zhang. Acute Necrotizing Encephalopathy: An Underrecognized Clinicoradiologic Disorder. Mediators of Inflammation. 2015; 2015:https://www.hindawi.com/journals/mi/2015/792578/cta/.
      3. Suri M. Genetic basis for acute necrotizing encephalopathy of childhood. Dev Med Child Neurol. January, 2010; 52(1):4-5. https://onlinelibrary.wiley.com/doi/10.1111/j.1469-8749.2009.03495.x/full.