Phenotypes associated with the disease developmental and epileptic encephalopathy, 31A (OMIM:616346):
- 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: 2/5. (PMID:25262651)
- Hypsarrhythmia (HP:0002521): Hypsarrhythmia is abnormal interictal high amplitude waves and a background of irregular spikes. There is continuous (during wakefulness), high-amplitude (>200 Hz), generalized polymorphic slowing with no organized background and multifocal spikes demonstrated by electroencephalography (EEG). Evidence: PCS. Frequency: 3/5. (PMID:25262651)
- Absent speech (HP:0001344): Complete lack of development of speech and language abilities. Evidence: PCS. Frequency: 5/5. (PMID:25262651)
- Inability to walk (HP:0002540): Incapability to ambulate. Evidence: PCS. Frequency: 4/5. (PMID:25262651)
- Developmental regression (HP:0002376): Loss of developmental skills, as manifested by loss of developmental milestones. Evidence: PCS. (PMID:25262651)
- Gait disturbance (HP:0001288): The term gait disturbance can refer to any disruption of the ability to walk. Evidence: PCS. Frequency: 1/5. (PMID:25262651)
- Focal impaired awareness seizure (HP:0002384): Focal impaired awareness seizure (or focal seizure with impaired or lost awareness) is a type of focal-onset seizure characterized by some degree (which may be partial) of impairment of the person's awareness of themselves or their surroundings at any point during the seizure. Evidence: PCS. Frequency: 2/5. (PMID:25262651)
- Atonic seizure (HP:0010819): Atonic seizure is a type of motor seizure characterized by a sudden loss or diminution of muscle tone without apparent preceding myoclonic or tonic event lasting about 1 to 2 seconds, involving head, trunk, jaw, or limb musculature. Evidence: PCS. Frequency: 2/10. (PMID:25262651)
- 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:25262651)
- Hypotonia (HP:0001252): Hypotonia is an abnormally low muscle tone (the amount of tension or resistance to movement in a muscle). Even when relaxed, muscles have a continuous and passive partial contraction which provides some resistance to passive stretching. Hypotonia thus manifests as diminished resistance to passive stretching. Hypotonia is not the same as muscle weakness, although the two conditions can co-exist. Evidence: PCS. Frequency: 5/5. (PMID:25262651)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. Frequency: 5/5. (PMID:25262651)
- Generalized hypotonia (HP:0001290): Generalized muscular hypotonia (abnormally low muscle tone). Evidence: PCS. Frequency: 2/5. (PMID:25262651)
- Myoclonic seizure (HP:0032794): A myoclonic seizure is a type of motor seizure characterized by 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: PCS. Frequency: 1/5. (PMID:25262651)
- Epileptic spasm (HP:0011097): A sudden flexion, extension, or mixed extension-flexion of predominantly proximal and truncal muscles that is usually more sustained than a myoclonic movement but not as sustained as a tonic seizure. Limited forms may occur: Grimacing, head nodding, or subtle eye movements. Epileptic spasms frequently occur in clusters. Infantile spasms are the best known form, but spasms can occur at all ages. Evidence: PCS. Frequency: 5/5. (PMID:25262651)
- Atypical absence seizure (HP:0007270): An atypical absence seizure is a type of generalized non-motor (absence) seizure characterized by interruption of ongoing activities and reduced responsiveness. In comparison to a typical absence seizure, changes in tone may be more pronounced, onset and/or cessation may be less abrupt, and the duration of the ictus and post-ictal recovery may be longer. Although not always available, an EEG often demonstrates slow (<3 Hz), irregular, generalized spike-wave activity. Evidence: PCS. Frequency: 3/5. (PMID:25262651)
- Atypical absence status epilepticus (HP:0011151): Atypical absence status epilepticus is a type of generalized non-convulsive status epilepticus without coma that is semiologically a prolonged atypical absence seizure. Evidence: PCS. Frequency: 2/5. (PMID:25262651)
- Tonic seizure (HP:0032792): A tonic seizure is a type of motor seizure characterized by unilateral or bilateral limb stiffening or elevation, often with neck stiffening. Evidence: PCS. Frequency: 3/5. (PMID:25262651)
- Diffuse cerebral atrophy (HP:0002506): Diffuse unlocalised atrophy affecting the cerebrum. Evidence: PCS. Frequency: 2/5. (PMID:25262651)
- Epileptic encephalopathy (HP:0200134): 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: PCS. Frequency: 5/5. (PMID:25262651)
- Self-injurious behavior (HP:0100716): Self-aggression. Evidence: PCS. Frequency: 2/5. (PMID:25262651)
- 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:25262651)
- 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: 5/5. (PMID:25262651)