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Children's Health

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Alternating Hemiplegia of Childhood

It is possible that the main title of the report Alternating Hemiplegia of Childhood is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.


  • AHC
  • alternating hemiplegia syndrome

Disorder Subdivisions

  • None

General Discussion

Alternating hemiplegia of childhood (AHC) is a rare neurodevelopmental disorder characterized by repeated episodes of weakness or paralysis that may affect one side of the body or the other (hemiplegia) or both sides of the body at once (quadriplegia). Additional episodic symptoms usually include intermittent abnormal eye movements, episodes of muscle stiffness or posturing (dystonia), and in a substantial percentage of cases, seizures. Delays in attaining developmental milestones (developmental delays), cognitive impairment, and persistent issues with balance and the presence of continuous dance-like movements of limbs or facial muscles (chorea) may occur independently of episodes of paralysis, weakness or stiffness and persist between episodes. The severity of AHC and the specific types of episodes that occur can vary dramatically from one individual to another. First symptoms usually begin before the age of 18 months. AHC is caused by mutations in the ATP1A3 gene in the majority of those affected.

AHC is a rare disorder that was first reported in the medical literature in 1971 by doctors Simon Verret and John C. Steele. They described an unusual disorder in eight children who demonstrated intermittent episodes of weakness, affecting first one side of the body, then the other, with onset in early childhood, including one child who manifested symptoms as early as 3 months of age. However, the disorder remained poorly understood for many years, in part, because of its rarity and complex and highly variable symptoms. More research is necessary to improve early diagnosis, understand the full range of symptoms, and develop more effective treatments. The recent identification of a causative gene for AHC should lead to a better understanding of the disorder and open new avenues for treatment.


The Arc
1825 K Street NW, Suite 1200
Washington, DC 20006
Tel: (202)534-3700
Fax: (202)534-3731
Tel: (800)433-5255
TDD: (817)277-0553

Epilepsy Foundation
8301 Professional Place
Landover, MD 20785-7223
Tel: (866)330-2718
Fax: (877)687-4878
Tel: (800)332-1000
TDD: (800)332-2070

Contact A Family
209-211 City Road
London, EC1V 1JN
United Kingdom
Tel: 02076088700
Fax: 02076088701
Tel: 08088083555

Alternating Hemiplegia of Childhood Foundation
31250 Plymouth Rd.
Livonia, MI 48150
Tel: (888)557-5757
Fax: (650)365-5798
Tel: (888)557-5757

NIH/National Institute of Neurological Disorders and Stroke
P.O. Box 5801
Bethesda, MD 20824
Tel: (301)496-5751
Fax: (301)402-2186
Tel: (800)352-9424
TDD: (301)468-5981

For a Complete Report:

This is an abstract of a report from the National Organization for Rare Disorders (NORD). A copy of the complete report can be downloaded free from the NORD website for registered users. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational therapies (if available), and references from medical literature. For a full-text version of this topic, go to and click on Rare Disease Database under "Rare Disease Information".

The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only. NORD recommends that affected individuals seek the advice or counsel of their own personal physicians.

It is possible that the title of this topic is not the name you selected. Please check the Synonyms listing to find the alternate name(s) and Disorder Subdivision(s) covered by this report

This disease entry is based upon medical information available through the date at the end of the topic. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder.

For additional information and assistance about rare disorders, please contact the National Organization for Rare Disorders at P.O. Box 1968, Danbury, CT 06813-1968; phone (203) 744-0100; web site or email

Last Updated: 1/25/2013
Copyright 1995, 1996, 2002, 2004, 2013 National Organization for Rare Disorders, Inc.

WebMD Medical Reference from the National Organization for Rare Disorders

Last Updated: May 28, 2015
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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