question: Epilepsy juvenile absence: The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs. Orpha Number: 1941 Disease 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. The Human Phenotype Ontology (HPO) provides the following list of features that have been reported in people with this condition. Much of the information in the HPO comes from Orphanet, a European rare disease database. If available, the list includes a rough estimate of how common a feature is (its frequency). Frequencies are based on a specific study and may not be representative of all studies. You can use the MedlinePlus Medical Dictionary for definitions of the terms below. Signs and Symptoms Approximate number of patients (when available) EEG with polyspike wave complexes Very frequent Generalized tonic-clonic seizures Very frequent Abnormality of the mouth Frequent Absence seizures Occasional Febrile seizures Occasional Myoclonus Very rare Autosomal dominant inheritance - EEG with spike-wave complexes (>3.5 Hz) - Generalized myoclonic seizures - Generalized tonic-clonic seizures on awakening - 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.