Phenotypes associated with the disease progressive myoclonic epilepsy type 8 (OMIM:616230):
- 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: 5/5. (PMID:24782409;PMID:30800706)
- Progressive neurologic deterioration (HP:0002344). Evidence: PCS. Frequency: 4/4. (PMID:24782409)
- Progressive (HP:0003676): Applies to a disease manifestation that increases in scope or severity over the course of time, i.e., that worsens with age. Evidence: PCS. (PMID:24782409)
- Delayed speech and language development (HP:0000750): A degree of language development that is significantly below the norm for a child of a specified age. Evidence: PCS. Frequency: 1/1. (PMID:30800706)
- Truncal ataxia (HP:0002078): Truncal ataxia is a sign of ataxia characterized by instability of the trunk. It usually occurs during sitting. Evidence: PCS. Frequency: 1/1. (PMID:30800706)
- Choreoathetosis (HP:0001266): Involuntary movements characterized by both athetosis (inability to sustain muscles in a fixed position) and chorea (widespread jerky arrhythmic movements). Evidence: PCS. Frequency: 1/1. (PMID:30800706)
- Gait disturbance (HP:0001288): The term gait disturbance can refer to any disruption of the ability to walk. Evidence: PCS. Frequency: 1/1. (PMID:30800706)
- Cerebellar atrophy (HP:0001272): Cerebellar atrophy is defined as a cerebellum with initially normal structures, in a posterior fossa with normal size, which displays enlarged fissures (interfolial spaces) in comparison to the foliae secondary to loss of tissue. Cerebellar atrophy implies irreversible loss of tissue and result from an ongoing progressive disease until a final stage is reached or a single injury, e.g. an intoxication or infectious event. Evidence: PCS. Frequency: 4/4. (PMID:24782409)
- Dysarthria (HP:0001260): Dysarthric speech is a general description referring to a neurological speech disorder characterized by poor articulation. Depending on the involved neurological structures, dysarthria may be further classified as spastic, flaccid, ataxic, hyperkinetic and hypokinetic, or mixed. Evidence: PCS. Frequency: 1/1. (PMID:30800706)
- Global developmental delay (HP:0001263): 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: PCS. Frequency: 5/5. (PMID:24782409;PMID:30800706)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. Frequency: 1/1. (PMID:30800706)
- EEG with photoparoxysmal response (HP:0010852): EEG abnormalities (epileptiform discharges) evoked by flashing lights or black and white striped patterns. Evidence: PCS. Frequency: 2/4. (PMID:24782409)
- Limb ataxia (HP:0002070): A kind of ataxia that affects movements of the extremities. Evidence: PCS. Frequency: 1/1. (PMID:30800706)
- Action myoclonus (HP:0034360): A type of myoclonus (arrhythmic muscular jerking) that is induced by voluntary movement. It is made worse by attempts at precise or coordinated movement (intention myoclonus) and may also be provoked by certain sensory stimuli. Evidence: PCS. Frequency: 5/5. (PMID:24782409;PMID:30800706)
- Nystagmus (HP:0000639): Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms. Evidence: PCS. Frequency: 1/1. (PMID:30800706)
- 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: 4/4. (PMID:24782409)
- Atrophy/Degeneration affecting the brainstem (HP:0007366). Evidence: PCS. Frequency: 5/5. (PMID:24782409;PMID:30800706)
- Autosomal recessive inheritance (HP:0000007): 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 individuals with two pathogenic alleles, either homozygotes (two copies of the same mutant allele) or compound heterozygotes (whereby each copy of a gene has a distinct mutant allele). Evidence: PCS. (PMID:24782409)
- Falls (HP:0002527). Evidence: PCS. Frequency: 1/1. (PMID:30800706)
- 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: TAS. (OMIM:616230)
- Myoclonus (HP:0001336): Very brief, involuntary random muscular contractions occurring at rest, in response to sensory stimuli, or accompanying voluntary movements. Evidence: PCS. Frequency: 5/5. (PMID:24782409;PMID:30800706)