- 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: 2/3. (PMID:26048982)
- Absent speech (HP:0001344): Complete lack of development of speech and language abilities. Evidence: PCS. Frequency: 3/3. (PMID:26048982)
- EEG abnormality (HP:0002353): Abnormality observed by electroencephalogram (EEG), which is used to record of the brain's spontaneous electrical activity from multiple electrodes placed on the scalp. Evidence: PCS. Frequency: 3/3. (PMID:26048982)
- Status epilepticus (HP:0002133): 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: PCS. Frequency: 1/3. (PMID:26048982)
- 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: 3/3. (PMID:26048982)
- Sleep disturbance (HP:0002360): An abnormal pattern in the quality, quantity, or characteristics of sleep. Evidence: PCS. Frequency: 3/3. (PMID:26048982)
- 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: 3/3. Onset: Infantile onset (HP:0003593). (PMID:26048982)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. Frequency: 6/6. (PMID:26048982)
- Motor delay (HP:0001270): A type of Developmental delay characterized by a delay in acquiring motor skills. Evidence: PCS. Frequency: 3/3. (PMID:26048982)
- Dyskinesia (HP:0100660): A movement disorder which consists of effects including diminished voluntary movements and the presence of involuntary movements. Evidence: PCS. Frequency: 3/3. (PMID:26048982)
- 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: PCS. Frequency: 3/3. (PMID:26048982)
- 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: PCS. Frequency: 3/3. (PMID:26048982)
- 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:26048982)
- Motor stereotypy (HP:0000733): Use of the same abnormal action in response to certain triggers or at random. They may be used as a way to regulate one's internal state but must otherwise have no apparent functional purpose. Evidence: PCS. Frequency: 3/3. (PMID:26048982)
- Agitation (HP:0000713): A state of excessive motor activity that is associated with mental distress or a feeling of substantial unease or inner tension. Distinguished from restlessness by the increased level of emotional distress and negative intensity of the experience. Agitation has a significant level of physical activity that is typically threatening to the self or others. Evidence: PCS. Frequency: 3/3. (PMID:26048982)
- Drooling (HP:0002307): Habitual flow of saliva out of the mouth. Evidence: PCS. Frequency: 3/3. (PMID:26048982)
- 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: 3/3. (PMID:26048982)
- Involuntary movements (HP:0004305): Involuntary contractions of muscle leading to involuntary movements of extremities, neck, trunk, or face. Evidence: PCS. Frequency: 3/3. (PMID:26048982)
These phenotypes are associated with the disease intellectual disability-epilepsy-extrapyramidal syndrome (OMIM:617171).