- Syndactyly (HP:0001159): Webbing or fusion of the fingers or toes, involving soft parts only or including bone structure. Bony fusions are referred to as "bony" syndactyly if the fusion occurs in a radio-ulnar axis. Fusions of bones of the fingers or toes in a proximo-distal axis are referred to as "symphalangism". Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:1942)
- 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: TAS. Frequency: Very rare (HP:0040284). (ORPHA:1942)
- 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: TAS. Frequency: Very rare (HP:0040284). (ORPHA:1942)
- Abnormal facial shape (HP:0001999): An abnormal morphology (form) of the face or its components. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:1942)
- Frontal balding (HP:0002292): Absence of hair in the anterior midline and/or parietal areas. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:1942)
- Unsteady gait (HP:0002317). Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:1942)
- Abnormal pyramidal sign (HP:0007256): Functional neurological abnormalities related to dysfunction of the pyramidal tract. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:1942)
- Focal-onset seizure (HP:0007359): 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. Frequency: Very rare (HP:0040284). (ORPHA:1942)
- Thick nasal alae (HP:0009928): Increase in bulk of the ala nasi. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:1942)
- Prominent forehead (HP:0011220): Forward prominence of the entire forehead, due to protrusion of the frontal bone. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:1942)
- Premature skin wrinkling (HP:0100678): The presence of an increased degree of wrinkling (irregular folds and indentations) of the skin as compared with age-related norms. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:1942)
- 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: TAS. Frequency: Very rare (HP:0040284). (ORPHA:1942)
- 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: TAS. Frequency: Frequent (HP:0040282). (ORPHA:1942)
- Bilateral tonic-clonic seizure with generalized onset (HP:0025190): A bilateral tonic-clonic seizure with generalized onset is a type of bilateral tonic-clonic seizure characterized by generalized onset; these seizures rapidly engage networks in both hemispheres at the start of the seizure. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:1942)
- Autistic behavior (HP:0000729): Persistent deficits in social interaction and communication and interaction as well as a markedly restricted repertoire of activity and interest as well as repetitive patterns of behavior. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:1942)
- 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: TAS. Frequency: Occasional (HP:0040283). (ORPHA:1942)
- 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: TAS. Frequency: Occasional (HP:0040283). (ORPHA:1942)
- Tremor (HP:0001337): An unintentional, oscillating to-and-fro muscle movement about a joint axis. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:1942)
- EEG with generalized slow activity (HP:0010845): Diffuse slowing of cerebral electrical activity recorded along the scalp by electroencephalography (EEG). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:1942)
- Simple febrile seizure (HP:0011171): A short generalized seizure, of a duration of <15 min, not recurring within 24 h, occurring during a febrile episode not caused by an acute disease of the nervous system intracranial infection or severe metabolic disturbance. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:1942)
- Interictal epileptiform activity (HP:0011182): Epileptiform activity refers to distinctive EEG waves or complexes distinguished from background activity found in in a proportion of human subjects with epilepsy, but which can also be found in subjects without seizures. Interictal epileptiform activity refers to such activity that occurs in the absence of a clinical or subclinical seizure. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:1942)
- Abnormal emotional state (HP:0100851): A disturbance in the experience or expression of emotion, characterized by alterations in valence, intensity, frequency, or duration. It may also involve emotional responses that are mismatched, exaggerated, or incongruent relative to internal expectations or external contextual stimuli, such as experiencing negative affect in response to neutral or positive events. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:1942)
- Brain imaging abnormality (HP:0410263): An anomaly of metabolism or structure of the brain identified by imaging. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:1942)
- Wide mouth (HP:0000154): Distance between the oral commissures more than 2 SD above the mean. Alternatively, an apparently increased width of the oral aperture (subjective). Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:1942)
- Thick lower lip vermilion (HP:0000179): Increased thickness of the lower lip, leading to a prominent appearance of the lower lip. The height of the vermilion of the lower lip in the midline is more than 2 SD above the mean. Alternatively, an apparently increased height of the vermilion of the lower lip in the frontal view (subjective). Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:1942)
- Thin upper lip vermilion (HP:0000219): Height of the vermilion of the upper lip in the midline more than 2 SD below the mean. Alternatively, an apparently reduced height of the vermilion of the upper lip in the frontal view (subjective). Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:1942)
- Microcephaly (HP:0000252): Head circumference below 2 standard deviations below the mean for age and gender. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:1942)
- Broad philtrum (HP:0000289): Distance between the philtral ridges, measured just above the vermilion border, more than 2 standard deviations above the mean, or alternatively, an apparently increased distance between the ridges of the philtrum. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:1942)
- Long philtrum (HP:0000343): Distance between nasal base and midline upper lip vermilion border more than 2 SD above the mean. Alternatively, an apparently increased distance between nasal base and midline upper lip vermilion border. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:1942)
- Wide nasal bridge (HP:0000431): Increased breadth of the nasal bridge (and with it, the nasal root). Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:1942)
- Anteverted nares (HP:0000463): Anteriorly-facing nostrils viewed with the head in the Frankfurt horizontal and the eyes of the observer level with the eyes of the subject. This gives the appearance of an upturned nose (upturned nasal tip). Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:1942)
- Microphthalmia (HP:0000568): A developmental anomaly characterized by abnormal smallness of one or both eyes. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:1942)
- 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: TAS. Frequency: Very rare (HP:0040284). (ORPHA:1942)
- Generalized myoclonic-atonic seizure (HP:0011170): A generalized myoclonic-atonic seizure is a type of generalized motor seizure characterized by a myoclonic jerk followed by an atonic motor component. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:1942)
- EEG with focal spike waves (HP:0011197): EEG with focal sharp transient waves of a duration less than 80 msec followed by a slow wave. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:1942)
- Hyperactivity (HP:0000752): Hyperactivity is a condition characterized by constant and unusually high levels of activity, even in situations where it is deemed inappropriate. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:1942)
- 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. Frequency: Frequent (HP:0040282). (ORPHA:1942)
- Generalized non-motor (absence) seizure (HP:0002121): A generalized non-motor (absence) seizure is a type of a type of dialeptic seizure that is of electrographically generalized onset. It is a generalized seizure characterized by an interruption of activities, a blank stare, and usually the person will be unresponsive when spoken to. Any ictal motor phenomena are minor in comparison to these non-motor features. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:1942)
- Generalized myoclonic seizure (HP:0002123): 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). (ORPHA:1942)
- Lack of peer relationships (HP:0002332): The state of not having relationships with peers outside of school or organized activity appropriate to developmental level. This may be caused by behavioral or physical barriers. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:1942)
- EEG with polyspike wave complexes (HP:0002392): The presence of complexes of repetitive spikes and waves in EEG. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:1942)
- Attention deficit hyperactivity disorder (HP:0007018): Attention deficit hyperactivity disorder (ADHD) manifests at age 2-3 years or by first grade at the latest. The main symptoms are distractibility, impulsivity, hyperactivity, and often trouble organizing tasks and projects, difficulty going to sleep, and social problems from being aggressive, loud, or impatient. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:1942)
- Reduced social responsiveness (HP:0012760): A reduced ability to participate in the back-and-forth flow of social interaction appropriate to culture and developmental level, which is normally characterized by an influence of the behavior of one person on the behavior of another person. This results in difficulty interacting with others through emotional, physical, or verbal communication. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:1942)
These phenotypes are associated with the disease Epilepsy with myoclonic-atonic seizures (ORPHA:1942).
The following phenotypes are NOT associated with this disease:
- 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: TAS. (ORPHA:1942)