- Bilateral tonic-clonic seizure (HP:0002069, a Human Phenotype Ontology term): A bilateral tonic-clonic seizure is a seizure defined by a tonic (bilateral increased tone, lasting seconds to minutes) and then a clonic (bilateral sustained rhythmic jerking) phase. Evidence: PCS. (PMID:31664039)
- Juvenile onset (HP:0003621, a Human Phenotype Ontology term): Onset of signs or symptoms of disease between the age of 5 and 15 years. Evidence: PCS. Frequency: 2/10. (PMID:31664039)
- Middle age onset (HP:0003596, a Human Phenotype Ontology term): A type of adult onset with onset of symptoms at the age of 40 to 60 years. Evidence: PCS. Frequency: 1/10. (PMID:31664039)
- Gait disturbance (HP:0001288, a Human Phenotype Ontology term): The term gait disturbance can refer to any disruption of the ability to walk. Evidence: PCS. Onset: Adult onset (HP:0003581, a Human Phenotype Ontology term). (PMID:31664039)
- Nonprogressive (HP:0003680, a Human Phenotype Ontology term): Applies to a disease manifestation that does not increase in scope or severity over the course of time, i.e., that does not worsen with age. Evidence: TAS. (OMIM:613608)
- Enhancement of the C-reflex (HP:0001340, a Human Phenotype Ontology term): Increase in amplitude of a long-loop response upon somatosensory evoked potential testing, representing an electrically evoked myoclonic response. Evidence: TAS. (OMIM:613608)
- Jerk-locked premyoclonus spikes (HP:0001351, a Human Phenotype Ontology term): Jerk-locked averaging (JLA) is used to record the timing and distribution of brain activity preceding brisk involuntary movements such as those observed in patients with myoclonus. JLA is capable of revealing a premyoclonus spike in the absence of paroxysmal activity in the routine EEG. Evidence: TAS. (OMIM:613608)
- EEG with photoparoxysmal response (HP:0010852, a Human Phenotype Ontology term): EEG abnormalities (epileptiform discharges) evoked by flashing lights or black and white striped patterns. Evidence: TAS. (OMIM:613608)
- Young adult onset (HP:0011462, a Human Phenotype Ontology term): Onset of disease at the age of between 16 and 40 years. Evidence: PCS. Frequency: 7/10. (PMID:31664039)
- Giant somatosensory evoked potentials (HP:0001312, a Human Phenotype Ontology term): An abnormal enlargement (i.e. increase in measured voltage) of somatosensory evoked potentials. Evidence: TAS. (OMIM:613608)
- Focal-onset seizure (HP:0007359, a Human Phenotype Ontology term): A focal-onset seizure is a type of seizure originating within networks limited to one hemisphere. They may be discretely localized or more widely distributed, and may originate in subcortical structures. Evidence: TAS. (OMIM:613608)
- Autosomal dominant inheritance (HP:0000006, a Human Phenotype Ontology term): A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in heterozygotes. In the context of medical genetics, an autosomal dominant disorder is caused when a single copy of the mutant allele is present. Males and females are affected equally, and can both transmit the disorder with a risk of 50% for each child of inheriting the mutant allele. Evidence: PCS. (PMID:31664039)
- Tremor (HP:0001337, a Human Phenotype Ontology term): An unintentional, oscillating to-and-fro muscle movement about a joint axis. Evidence: PCS. Frequency: 8/10. (PMID:31664039)
- Myoclonus (HP:0001336, a Human Phenotype Ontology term): Very brief, involuntary random muscular contractions occurring at rest, in response to sensory stimuli, or accompanying voluntary movements. Evidence: PCS. Onset: Adult onset (HP:0003581, a Human Phenotype Ontology term). (PMID:31664039)
These phenotypes are associated with the disease epilepsy, familial adult myoclonic, 3 (OMIM:613608, an entry in Online Mendelian Inheritance in Man).