- Dystonia (HP:0001332, a Human Phenotype Ontology term): An abnormally increased muscular tone that causes fixed abnormal postures. There is a slow, intermittent twisting motion that leads to exaggerated turning and posture of the extremities and trunk. Evidence: TAS. Frequency: Very frequent (HP:0040281, a Human Phenotype Ontology term). (ORPHA:352596)
- 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: TAS. Frequency: Very frequent (HP:0040281, a Human Phenotype Ontology term). (ORPHA:352596)
- Recurrent upper respiratory tract infections (HP:0002788, a Human Phenotype Ontology term): An increased susceptibility to upper respiratory tract infections as manifested by a history of recurrent upper respiratory tract infections (running ears - otitis, sinusitis, pharyngitis, tonsillitis). Evidence: TAS. Frequency: Very frequent (HP:0040281, a Human Phenotype Ontology term). (ORPHA:352596)
- Abnormal pyramidal sign (HP:0007256, a Human Phenotype Ontology term): Functional neurological abnormalities related to dysfunction of the pyramidal tract. Evidence: TAS. Frequency: Very frequent (HP:0040281, a Human Phenotype Ontology term). (ORPHA:352596)
- Microcephaly (HP:0000252, a Human Phenotype Ontology term): Head circumference below 2 standard deviations below the mean for age and gender. Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:352596)
- EEG with irregular generalized spike and wave complexes (HP:0001326, a Human Phenotype Ontology term): EEG shows spikes (<80 ms) and waves, which are recorded over the entire scalp and do not have a specific frequency. Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:352596)
- Generalized myoclonic seizure (HP:0002123, a Human Phenotype Ontology term): A generalized myoclonic seizure is a type of generalized motor seizure characterized by bilateral, sudden, brief (<100 ms) involuntary single or multiple contraction of muscles or muscle groups of variable topography (axial, proximal limb, distal). Myoclonus is less regularly repetitive and less sustained than is clonus. Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:352596)
- Status epilepticus (HP:0002133, a Human Phenotype Ontology term): Status epilepticus is a type of prolonged seizure resulting either from the failure of the mechanisms responsible for seizure termination or from the initiation of mechanisms which lead to abnormally prolonged seizures (after time point t1). It is a condition that can have long-term consequences (after time point t2), including neuronal death, neuronal injury, and alteration of neuronal networks, depending on the type and duration of seizures. Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:352596)
- Delayed CNS myelination (HP:0002188, a Human Phenotype Ontology term): Delayed myelination in the central nervous system. Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:352596)
- Developmental regression (HP:0002376, a Human Phenotype Ontology term): Loss of developmental skills, as manifested by loss of developmental milestones. Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:352596)
- Generalized neonatal hypotonia (HP:0008935, a Human Phenotype Ontology term): Muscular hypotonia (abnormally low muscle tone) manifesting in the neonatal period and affecting the entire musculature. Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:352596)
- Feeding difficulties (HP:0011968, a Human Phenotype Ontology term): Impaired ability to eat related to problems gathering food and getting ready to suck, chew, or swallow it. Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:352596)
- Epileptic encephalopathy (HP:0200134, a Human Phenotype Ontology term): A condition in which epileptiform abnormalities are believed to contribute to the progressive disturbance in cerebral function. Epileptic encephalaopathy is characterized by (1) electrographic EEG paroxysmal activity that is often aggressive, (2) seizures that are usually multiform and intractable, (3) cognitive, behavioral and neurological deficits that may be relentless, and (4) sometimes early death. Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:352596)
- Excessive daytime somnolence (HP:0001262, a Human Phenotype Ontology term): A state of abnormally strong desire for sleep during the daytime. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:352596)
- Global developmental delay (HP:0001263, a Human Phenotype Ontology term): A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:352596)
- Hemiparesis (HP:0001269, a Human Phenotype Ontology term): Loss of strength in the arm, leg, and sometimes face on one side of the body. Hemiplegia refers to a complete loss of strength, whereas hemiparesis refers to an incomplete loss of strength. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:352596)
- Abnormality of extrapyramidal motor function (HP:0002071, a Human Phenotype Ontology term): A neurological condition related to lesions of the basal ganglia leading to typical abnormalities including akinesia (inability to initiate changes in activity and perform volitional movements rapidly and easily), muscular rigidity (continuous contraction of muscles with constant resistance to passive movement), chorea (widespread arrhythmic movements of a forcible, rapid, jerky, and restless nature), athetosis (inability to sustain the muscles of the fingers, toes, or other group of muscles in a fixed position), and akathisia (inability to remain motionless). Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:352596)
- Hemiplegia (HP:0002301, a Human Phenotype Ontology term): Paralysis (complete loss of muscle function) in the arm, leg, and in some cases the face on one side of the body. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:352596)
- Diffuse cerebral atrophy (HP:0002506, a Human Phenotype Ontology term): Diffuse unlocalised atrophy affecting the cerebrum. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:352596)
- Poor visual behavior for age (HP:0025152, a Human Phenotype Ontology term): Lack of visual responsiveness or decrease in visual capabilities suggesting a lack of visual responsiveness or decrease in visual capabilities in an infant or young child in which visual behavior fails to meet normal developmental milestones. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:352596)
- Diffuse cerebellar atrophy (HP:0100275, a Human Phenotype Ontology term): Diffuse unlocalised atrophy affecting the cerebellum. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:352596)
- Optic atrophy (HP:0000648, a Human Phenotype Ontology term): Atrophy of the optic nerve. Optic atrophy results from the death of the retinal ganglion cell axons that comprise the optic nerve and manifesting as a pale optic nerve on fundoscopy. Evidence: TAS. Frequency: Very rare (HP:0040284, a Human Phenotype Ontology term). (ORPHA:352596)
These phenotypes are associated with the disease Progressive myoclonic epilepsy with dystonia (ORPHA:352596, an Orphanet rare-disease identifier).