Phenotypes associated with the disease Landau-Kleffner syndrome (ORPHA:98818):
- Seizure (HP:0001250): A seizure is an intermittent abnormality of nervous system physiology characterized by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:98818)
- Loss of speech (HP:0002371). Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:98818)
- Aphasia (HP:0002381): An acquired language impairment of some or all of the abilities to produce or comprehend speech and to read or write. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:98818)
- Language impairment (HP:0002463): Language impairment is a deficit in comprehension or production of language that includes reduced vocabulary, limited sentence structure, or impairments in written or spoken communication. Language abilities are substantially and quantifiably below age expectations. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:98818)
- Speech apraxia (HP:0011098): A type of apraxia that is characterized by difficulty or inability to execute speech movements because of problems with coordination and motor problems, leading to incorrect articulation. An increase of errors with increasing word and phrase length may occur. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:98818)
- Interictal EEG abnormality (HP:0025373): Interictal refers to a period of time between epileptic seizures. Electroencephalographic (EEG) patterns are important in the differential diagnosis of epilepsy, and the EEG is almost always abnormal during a seizure. Some persons with seizures may show EEG abnormalities between seizures, while others do not. In some cases, multiple interictal EEGs must be recorded before an abnormality is observed. In most cases the electrographic pattern of seizure onset is completely different from the activity recorded during interictal discharge. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:98818)
- Spoken word recognition deficit (HP:0030391): Reduced ability of lexical discrimination, which refers to the process of distinguishing a stimulus word from other phonologically similar words. Lexical discrimination can be defined as the process of correctly identifying words in the mental lexicon to match the phonological input of a stimulus. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:98818)
- Continuous spike and waves during slow sleep (HP:0031491): Diffuse, bilateral and recently also unilateral or focal localization spike-wave occurring in slow sleep or non-rapid eye movement sleep. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:98818)
- Atypical behavior (HP:0000708): Atypical behavior is an abnormality in a person's actions that can be controlled or modulated by the will of the individual. While abnormal behaviors can be difficult to control, they are distinct from other abnormal actions that cannot be affected by the individual's will. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98818)
- 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: Frequent (HP:0040282). (ORPHA:98818)
- 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:98818)
- Developmental regression (HP:0002376): Loss of developmental skills, as manifested by loss of developmental milestones. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98818)
- 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:98818)
- Social and occupational deterioration (HP:0007086). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98818)
- Speech articulation difficulties (HP:0009088): Impairment in the physical production of speech sounds. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98818)
- Focal motor seizure (HP:0011153): A type of focal-onset seizure characterized by a motor sign as its initial semiological manifestation. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98818)
- EEG with generalized epileptiform discharges (HP:0011198): EEG discharges recorded on the entire scalp typically seen in persons with epilepsy. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98818)
- EEG with frontal focal spikes (HP:0012015): EEG with focal sharp transient waves of a duration less than 80 msec in the frontal region. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98818)
- EEG with temporal focal spikes (HP:0012018): EEG with focal sharp transient waves of a duration less than 80 msec in the temporal region. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98818)
- 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:98818)
- Emotional lability (HP:0000712): Unstable emotional experiences and frequent mood changes; emotions that are easily aroused, intense, and/or disproportionate to events and circumstances. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98818)
- Depression (HP:0000716): Frequently experiencing feelings of being down, miserable, and/or hopeless; struggling to recover from these moods; having a pessimistic outlook on the future; feeling a pervasive sense of shame; having a low self-worth; experiencing thoughts of suicide and engaging in suicidal behavior. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98818)
- Aggressive behavior (HP:0000718): Behavior or an act aimed at harming a person, animal, or physical property (e.g., acts of physical violence; shouting, swearing, and using harsh language; slashing someone's tires). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98818)
- Short attention span (HP:0000736): Reduced attention span characterized by distractibility and impulsivity. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98818)
- Anxiety (HP:0000739): Intense feelings of nervousness, tension, or panic often arise in response to interpersonal stresses. There is worry about the negative effects of past unpleasant experiences and future negative possibilities. Individuals may feel fearful, apprehensive, or threatened by uncertainty, and they may also have fears of falling apart or losing control. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98818)
- 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: Occasional (HP:0040283). (ORPHA:98818)
- Slurred speech (HP:0001350): Abnormal coordination of muscles involved in speech. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98818)
- Gait ataxia (HP:0002066): A type of ataxia characterized by the impairment of the ability to coordinate the movements required for normal walking. Gait ataxia is characteirzed by a wide-based staggering gait with a tendency to fall. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98818)
- 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: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98818)
- Mutism (HP:0002300): Complete lack of speech or verbal communication in a person despite attempts to engage in conversation. Mutism as a phenomena assumes the individual has previous capacity for speech and in the pediatric population it assumes that the person is past the age of typical language development. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98818)
- Memory impairment (HP:0002354): An impairment of memory as manifested by a reduced ability to remember things such as dates and names, and increased forgetfulness. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98818)
- Frequent falls (HP:0002359). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98818)
- Sleep disturbance (HP:0002360): An abnormal pattern in the quality, quantity, or characteristics of sleep. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98818)
- 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: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98818)
- Steppage gait (HP:0003376): An abnormal gait pattern that arises from weakness of the pretibial and peroneal muscles due to a lower motor neuron lesion. Affected patients have footdrop and are unable to dorsiflex and evert the foot. The leg is lifted high on walking so that the toes clear the ground, and there may be a slapping noise when the foot strikes the ground again. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98818)
- Difficulty standing (HP:0003698). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98818)
- 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: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98818)
- Focal myoclonic seizure (HP:0011166): A type of focal motor seizure characterized by sudden, brief (<100 ms) involuntary single or multiple contraction(s) of muscles(s) or muscle groups of variable topography (axial, proximal limb, distal). Myoclonus is less regularly repetitive and less sustained than is clonus. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98818)
- Generalized clonic seizure (HP:0011169): Generalized clonic seizure is a type of generalized motor seizure characterized by sustained bilateral jerking, either symmetric or asymmetric, that is regularly repetitive and involves the same muscle groups. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98818)
- Nocturnal seizures (HP:0031951): Seizures that occur while the affected individual is sleeping. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98818)
- Non-convulsive status epilepticus without coma (HP:0032671): A type of status epilepticus without prominent motor symptoms in the absence of coma. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98818)
- Impulsivity (HP:0100710): Acting on the spur of the moment or on a momentary basis without consideration of outcomes; having difficulty establishing or following plans; experiencing a sense of urgency and engaging in behavior that is uninhibited, cannot be inhibited, and is uncontrolled. The possibility of repression is inconceivable. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98818)
- Autoimmune antibody positivity (HP:0030057): The presence of an antibody in the blood circulation that is directed against the organism's own cells or tissues. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:98818)
- 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:98818)