National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Alternating hemiplegia of childhood



Other Names:
Alternating hemiplegia syndrome; AHC; Alternating hemiplegia
Categories:

Alternating hemiplegia of childhood (AHC) is a neurological disorder that usually affects children before 18 months of age. Classic AHC causes recurrent episodes of paralysis (hemiplegia) that involve one or both sides of the body, multiple limbs, or a single limb. The paralysis may affect different parts of the body at different times and may be brief or last for several days. A characteristic feature of AHC is that symptoms disappear during sleep and return upon waking. Many affected children display some degree of developmental delay, abnormal eye (oculomotor) movements, uncontrolled limb movements (including ataxia, dystonia, and choreoathetosis) and seizures.[1][2]  

The majority of cases of AHC are caused by a new change (called a mutation or pathogenic variant) in the ATP1A3 gene that is not inherited. Thus, most patients with AHC do not have a family history of the disorder. A small number of cases of AHC are caused by changes in the ATP1A2 gene.[1][2] When this condition does run in families, it follows an autosomal dominant pattern of inheritance.[2]Treatment is limited to therapies that can help reduce the severity and duration of symptoms.[1] 
Last updated: 5/24/2018

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
30%-79% of people have these symptoms
Bilateral tonic-clonic seizure
Grand mal seizures
0002069
Percent of people who have these symptoms is not available through HPO
Autosomal dominant inheritance 0000006
Choreoathetosis 0001266
Dystonia 0001332
Episodic hemiplegia 0012194
Episodic quadriplegia 0200072
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific
Mental-retardation
[ more ]
0001249
Mental deterioration
Cognitive decline
Cognitive decline, progressive
Intellectual deterioration
Progressive cognitive decline
[ more ]
0001268
Nystagmus
Involuntary, rapid, rhythmic eye movements
0000639
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Last updated: 7/1/2020

Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources


Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.

Conditions with similar signs and symptoms from Orphanet
Differential diagnoses includes infantile epilepsy syndrome, benign nocturnal alternating hemiplegia of childhood, as well as allelic disorders with overlapping clinical features, such as rapid-onset dystonia-parkinsonism, familial or sporadic hemiplegic migraine and Moyamoya disease. Neurological, metabolic and vascular syndromes with similar clinical features should also be excluded.
Visit the Orphanet disease page for more information.

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • ClinicalTrials.gov lists trials that are related to Alternating hemiplegia of childhood. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

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

Social Networking Websites

  • RareConnect has an online community for patients and families with this condition so they can connect with others and share their experiences living with a rare disease. The project is a joint collaboration between EURORDIS (European Rare Disease Organisation) and NORD (National Organization for Rare Disorders).

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.

Where to Start

In-Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Alternating hemiplegia of childhood. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.


  1. National Institute of Neurological Disorders and Stroke (NINDS). Alternating Hemiplegia of Childhood. March 6, 2018; https://www.ninds.nih.gov/Disorders/All-Disorders/Alternating-Hemiplegia-Information-Page.
  2. Alternating hemiplegia of childhood. Genetics Home Reference (GHR). September 2016; https://ghr.nlm.nih.gov/condition/alternating-hemiplegia-of-childhood.