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Disease Profile

Epilepsy juvenile absence

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.
1-9 / 100 000

3,310 - 29,790

US Estimated

1-9 / 100 000

5,135 - 46,215

Europe Estimated

Age of onset

Adolescent

ICD-10

G40.3

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)

JAE; Childhood absence epilepsy; Juvenile absence epilepsy

Categories

Congenital and Genetic Diseases; Nervous System Diseases

Summary

The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.
orphanet

Orpha Number: 1941

Definition
Juvenile absence epilepsy (JAE) is a genetic epilepsy with onset occurring around puberty. JAE is characterized by sporadic occurrence of absence seizures, frequently associated with a long-life prevalence of generalized tonic-clonic seizures (GTCS) and sporadic myoclonic jerks.

Epidemiology
The incidence of JAE is still unknown but it accounts for approximately 2-3% of patients with adult epilepsy in general, and about 8-10% of patients with genetic generalized epilepsy (GGE). No sex predominance has been observed.

Clinical description
JAE is characterized by sporadic occurrence of absence seizures (only one or a few absences daily; 100% of cases), frequently associated with a long-life prevalence of generalized tonic-clonic seizures (GTCS; 80%) and sporadic myoclonic jerks (20%). The seizures onset is typically between 9 and 13 years of age and it manifests as a ''staring spell'' that can be accompanied by atonic postures such as drooping of the head and/or automatisms such as lip smacking. GTCS and myoclonic seizures often occur 1-10 years after the absence seizure onset. Patients with JAE usually develop normally, although uncontrolled absence seizures may have an impact on their ability to learn at school.

Etiology
The exact etiology of JAE is still elusive. However, genetic mutations for voltage-gated sodium channels (CACNB4 gene (2q22-q23)), potassium channels (CLCN2 gene (3q27.1)), and EFHC1 (6p12.3) may be involved in a subset of patients. Moreover, different mutations have been found in genes for GABA receptors (ligand ion channels), specifically in the GABRA1 gene (5q34).

Diagnostic methods
Diagnosis relies on the clinical features and on electroencephalogram (EEG) recorded awake and during sleep, that displays a generalized 3-4 Hz spike-and-slow-wave complexes.

Differential diagnosis
Differential diagnosis includes childhood absence epilepsy, juvenile myoclonic epilepsy, Jeavons syndrome (see these terms).

Genetic counseling
The transmission is still unknown although an increased risk for first degree related parents to develop JME may exist.

Management and treatment
The antiepileptic drugs of choice are valproic acid (VPA) and lamotrigine (LTG). In cases where VPA deals with only partial seizure control, add-on of LTG (GTCS) or ethosuximide (absence seizures) can be beneficial.

Prognosis
Prognosis of JAE is usually favorable with good therapy responsiveness. Generally, seizure freedom can be achieved with antiepileptic medication in 62-84% of all patients with JAE. However, the occurrence of GTCS predicts a worse prognosis.

Visit the Orphanet disease page for more resources.

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
Bilateral tonic-clonic seizure
Grand mal seizures
0002069
EEG with polyspike wave complexes
0002392
30%-79% of people have these symptoms
Abnormality of eye movement
Abnormal eye movement
Abnormal eye movements
Eye movement abnormalities
Eye movement issue

[ more ]

0000496
Abnormality of the mouth
Abnormal mouth
0000153
5%-29% of people have these symptoms
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
1%-4% of people have these symptoms
Myoclonus
0001336
Percent of people who have these symptoms is not available through HPO
Autosomal dominant inheritance
0000006
Bilateral tonic-clonic seizure on awakening
Morning generalized tonic-clonic seizures
0007193
EEG with spike-wave complexes (>3.5 Hz)
0010849
Generalized myoclonic seizure
0002123

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

  • 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.

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

  • 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 juvenile absence. Click on the link to view a sample search on this topic.