Phenotypes associated with the disease epilepsy, familial adult myoclonic, 2 (OMIM:607876):
- Bilateral tonic-clonic seizure (HP:0002069): 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. Frequency: 118/229. (OMIM:607876)
- Migraine (HP:0002076): Migraine is a chronic neurological disorder characterized by episodic attacks of headache and associated symptoms. Evidence: PCS. Frequency: 42/130. (PMID:31664034)
- Adult onset (HP:0003581): Onset of disease manifestations in adulthood, defined here as at the age of 16 years or later. Evidence: PCS. (PMID:31664034)
- Enhancement of the C-reflex (HP:0001340): Increase in amplitude of a long-loop response upon somatosensory evoked potential testing, representing an electrically evoked myoclonic response. Evidence: IEA. (OMIM:607876)
- Jerk-locked premyoclonus spikes (HP:0001351): 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: IEA. (OMIM:607876)
- Nonprogressive (HP:0003680): 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: IEA. (OMIM:607876)
- Ataxia (HP:0001251): Ataxia refers to impaired coordination of voluntary muscle movement. Cerebellar ataxia refers to ataxia due to dysfunction of the cerebellum. This causes a variety of elementary neurological deficits including asynergy (lack of coordination between muscles, limbs and joints), dysmetria (lack of ability to judge distances that can lead to under- or overshoot in grasping movements), and dysdiadochokinesia (inability to perform rapid movements requiring antagonizing muscle groups to be switched on and off repeatedly). Evidence: PCS. Frequency: 3/201. (PMID:31664034)
- EEG with photoparoxysmal response (HP:0010852): EEG abnormalities (epileptiform discharges) evoked by flashing lights or black and white striped patterns. Evidence: TAS. (OMIM:607876)
- Cognitive impairment (HP:0100543): Abnormal cognition is characterized by deficits in thinking, reasoning, or remembering. Evidence: TAS. Frequency: Occasional (HP:0040283). (OMIM:607876)
- Dementia (HP:0000726): A loss of global cognitive ability of sufficient amount to interfere with normal social or occupational function. Dementia represents a loss of previously present cognitive abilities, generally in adults, and can affect memory, thinking, language, judgment, and behavior. Evidence: PCS. Frequency: 5/199. (PMID:31664034)
- Giant somatosensory evoked potentials (HP:0001312): An abnormal enlargement (i.e. increase in measured voltage) of somatosensory evoked potentials. Evidence: IEA. (OMIM:607876)
- Autosomal dominant inheritance (HP:0000006): 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:31664034)
- EEG with irregular generalized spike and wave complexes (HP:0001326): EEG shows spikes (<80 ms) and waves, which are recorded over the entire scalp and do not have a specific frequency. Evidence: IEA. (OMIM:607876)
- Intellectual disability (HP:0001249): The term intellectual disability or intellectual developmental disorder is used to describe significantly sub-average intellectual and adaptive functioning based on clinical assessment and as measured by individually administered, appropriately normed, standardized and validated tests of intellectual functioning and adaptive behavior, with onset during the developmental period from infancy through adolescence. Evidence: PCS. Frequency: 9/193. (PMID:31664034)
- Tremor (HP:0001337): An unintentional, oscillating to-and-fro muscle movement about a joint axis. Evidence: PCS. (PMID:31664034)
- Blepharospasm (HP:0000643): A focal dystonia that affects the muscles of the eyelids and brow, associated with involuntary recurrent spasm of both eyelids. Evidence: TAS. (OMIM:607876)
- Myoclonus (HP:0001336): Very brief, involuntary random muscular contractions occurring at rest, in response to sensory stimuli, or accompanying voluntary movements. Evidence: PCS. Frequency: 195/227. (PMID:31664034)