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Disease Profile

Epilepsy with myoclonic-atonic seizures

Prevalence
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.

Unknown

Age of onset

Childhood

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ICD-10

G40.4

Inheritance

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

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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

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X-linked
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.

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

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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.

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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.

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Not applicable

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Other names (AKA)

Myoclonic astatic epilepsy; Doose syndrome; Epilepsy with myoclonic-astatic seizures;

Categories

Congenital and Genetic Diseases; Nervous System Diseases

Summary

Epilepsy with myoclonic-atonic seizures is a rare epilepsy syndrome of early childhood. It is characterized by seizures of many different types, most often myoclonicatonic, astatic, or generalized tonic-clonic seizures. Seizures can be followed by drop attacks, which can lead to falls and injuries. Absence seizures may occur. People with the condition may experience several seizures each day. The epilepsy may result in a delay or regression of skills. Autistic features and ataxic (poorly controlled) movements have been reported in some cases.

Treatment may include valproic acid alone or with other antiepileptic drugs. Ketogenic (high fat, low carb) diet has been successful in some. Long term outlook ranges from persistent seizures that do not respond to treatment and intellectual disability, to complete seizure remission after several years and normal outcome. Changes in the SCN1A, SCN1B, GABRG2, CHD2, and SLC6A1 genes can cause or contribute to epilepsy with myoclonic-atonic seizures. However, in many cases the cause remains unknown. Epilepsy with myoclonic-atonic seizures can be inherited from an affected parent or occur for the first time in a family as a sporadic disease.[1][2]

Symptoms

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.

Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Ataxia
0001251
Atonic seizure
0010819
EEG with spike-wave complexes (>3.5 Hz)
0010849
Generalized myoclonic seizure
0002123
Generalized myoclonic-atonic seizure
0011170
30%-79% of people have these symptoms
Abnormal brain FDG positron emission tomography
0012658
Developmental regression
Loss of developmental milestones
Mental deterioration in childhood

[ more ]

0002376
Dysarthria
Difficulty articulating speech
0001260
EEG with abnormally slow frequencies
0011203
Epileptic encephalopathy
0200134
Mental deterioration
Cognitive decline
Cognitive decline, progressive
Intellectual deterioration
Progressive cognitive decline

[ more ]

0001268
Status epilepticus
Repeated seizures without recovery between them
0002133
5%-29% of people have these symptoms
Aggressive behavior
Aggression
Aggressive behaviour
Aggressiveness

[ more ]

0000718
Autistic behavior
0000729
Febrile seizure (within the age range of 3 months to 6 years)
Fever induced seizures
0002373
Generalized non-motor (absence) seizure
Brief seizures with staring spells
0002121
Global developmental delay
0001263
Impulsivity
Impulsive
0100710
Myoclonus
0001336
Photosensitive tonic-clonic seizure
0007207
Scoliosis
0002650
Tremor
0001337
Percent of people who have these symptoms is not available through HPO
Autosomal dominant inheritance
0000006
Eyelid myoclonus
0025097
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific
Mental-retardation

[ more ]

0001249

Diagnosis

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

  • Orphanet lists international laboratories offering diagnostic testing for this condition.

    Organizations

    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

      • SLC6A1 Gene Families is a closed Facebook group for people with a loved one with a SLC6A1 gene change or mutation.

        Organizations Providing General Support

          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.

          Where to Start

          • Doose Syndrome Alliance provides detailed information on myoclonic astatic epilepsy. Click on the link to view this information.
          • Epilepsy Action provides information on the symptoms and treatment of myoclonic astatic epilepsy. Click on the link to view this information.
          • Johns Hopkins Epilepsy Center provides information on myoclonic astatic epilepsy. Click on the link to view this information.

            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 Epilepsy with myoclonic-atonic seizures. Click on the link to view a sample search on this topic.

              References

              1. Myoclonic-astastic epilepsy. Orphanet. https://www.orpha.net/consor/cgi-bin/OC_Exp.php?Lng=GB&Expert=1942. Accessed 7/25/2018.
              2. Carvill GL, McMahon JM, Schneider A et al.,. Mutations in the GABA transporter SLC6A1 cause epilepsy with myoclonic-atonic seizures. Am J Hum Genetics. 2015 May 7; 96(5):808-815. Accessed 7/25/2018.