- Microcephaly (HP:0000252, a Human Phenotype Ontology term): Head circumference below 2 standard deviations below the mean for age and gender. Evidence: TAS. Frequency: Very frequent (HP:0040281, a Human Phenotype Ontology term). (ORPHA:72)
- Atypical behavior (HP:0000708, a Human Phenotype Ontology term): 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: Very frequent (HP:0040281, a Human Phenotype Ontology term). (ORPHA:72)
- Autistic behavior (HP:0000729, a Human Phenotype Ontology term): 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: Very frequent (HP:0040281, a Human Phenotype Ontology term). (ORPHA:72)
- Inappropriate laughter (HP:0000748, a Human Phenotype Ontology term): Laughing that may be excessive and/or inappropriate in context (e.g., laughing at a funeral while others are crying). Evidence: TAS. Frequency: Very frequent (HP:0040281, a Human Phenotype Ontology term). (ORPHA:72)
- Delayed speech and language development (HP:0000750, a Human Phenotype Ontology term): A degree of language development that is significantly below the norm for a child of a specified age. Evidence: TAS. Frequency: Very frequent (HP:0040281, a Human Phenotype Ontology term). (ORPHA:72)
- Hyperactivity (HP:0000752, a Human Phenotype Ontology term): Hyperactivity is a condition characterized by constant and unusually high levels of activity, even in situations where it is deemed inappropriate. Evidence: TAS. Frequency: Very frequent (HP:0040281, a Human Phenotype Ontology term). (ORPHA:72)
- Seizure (HP:0001250, a Human Phenotype Ontology term): 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, a Human Phenotype Ontology term). (ORPHA:72)
- Ataxia (HP:0001251, a Human Phenotype Ontology term): 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: Very frequent (HP:0040281, a Human Phenotype Ontology term). (ORPHA:72)
- Motor delay (HP:0001270, a Human Phenotype Ontology term): A type of Developmental delay characterized by a delay in acquiring motor skills. Evidence: TAS. Frequency: Very frequent (HP:0040281, a Human Phenotype Ontology term). (ORPHA:72)
- Tremor (HP:0001337, a Human Phenotype Ontology term): An unintentional, oscillating to-and-fro muscle movement about a joint axis. Evidence: TAS. Frequency: Very frequent (HP:0040281, a Human Phenotype Ontology term). (ORPHA:72)
- Cerebral cortical atrophy (HP:0002120, a Human Phenotype Ontology term): Atrophy of the cortex of the cerebrum. Evidence: TAS. Frequency: Very frequent (HP:0040281, a Human Phenotype Ontology term). (ORPHA:72)
- Broad-based gait (HP:0002136, a Human Phenotype Ontology term): An abnormal gait pattern in which persons stand and walk with their feet spaced widely apart. This is often a component of cerebellar ataxia. Evidence: TAS. Frequency: Very frequent (HP:0040281, a Human Phenotype Ontology term). (ORPHA:72)
- Abnormal speech pattern (HP:0002167, a Human Phenotype Ontology term): An abnormality in the sound (volume) or cadence (rate) of speech. Evidence: TAS. Frequency: Very frequent (HP:0040281, a Human Phenotype Ontology term). (ORPHA:72)
- EEG abnormality (HP:0002353, a Human Phenotype Ontology term): 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: TAS. Frequency: Very frequent (HP:0040281, a Human Phenotype Ontology term). (ORPHA:72)
- Sleep disturbance (HP:0002360, a Human Phenotype Ontology term): An abnormal pattern in the quality, quantity, or characteristics of sleep. Evidence: TAS. Frequency: Very frequent (HP:0040281, a Human Phenotype Ontology term). (ORPHA:72)
- Poor speech (HP:0002465, a Human Phenotype Ontology term). Evidence: TAS. Frequency: Very frequent (HP:0040281, a Human Phenotype Ontology term). (ORPHA:72)
- Severe intellectual disability (HP:0010864, a Human Phenotype Ontology term): Severe intellectual disability (ID) is defined as a type of ID characterized by severely sub-average adaptive functioning and intellectual functioning, with an intelligence quotient (IQ) the range of 20-34. Evidence: TAS. Frequency: Very frequent (HP:0040281, a Human Phenotype Ontology term). (ORPHA:72)
- Severe global developmental delay (HP:0011344, a Human Phenotype Ontology term): A severe delay in the achievement of motor or mental milestones in the domains of development of a child. Evidence: TAS. Frequency: Very frequent (HP:0040281, a Human Phenotype Ontology term). (ORPHA:72)
- Self-injurious behavior (HP:0100716, a Human Phenotype Ontology term): Self-aggression. Evidence: TAS. Frequency: Very frequent (HP:0040281, a Human Phenotype Ontology term). (ORPHA:72)
- Wide mouth (HP:0000154, a Human Phenotype Ontology term): 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: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:72)
- Astigmatism (HP:0000483, a Human Phenotype Ontology term): A type of refraction error associated with abnormal curvatures on the anterior and/or posterior surface of the cornea. Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:72)
- Strabismus (HP:0000486, a Human Phenotype Ontology term): A misalignment of the eyes so that the visual axes deviate from bifoveal fixation. The classification of strabismus may be based on a number of features including the relative position of the eyes, whether the deviation is latent or manifest, intermittent or constant, concomitant or otherwise and according to the age of onset and the relevance of any associated refractive error. Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:72)
- Hypopigmentation of the skin (HP:0001010, a Human Phenotype Ontology term): A reduction of skin color related to a decrease in melanin production and deposition. Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:72)
- Obesity (HP:0001513, a Human Phenotype Ontology term): Accumulation of substantial excess body fat. Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:72)
- Abnormal facial shape (HP:0001999, a Human Phenotype Ontology term): An abnormal morphology (form) of the face or its components. Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:72)
- Constipation (HP:0002019, a Human Phenotype Ontology term): Infrequent or difficult evacuation of feces. Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:72)
- Gastroesophageal reflux (HP:0002020, a Human Phenotype Ontology term): A condition in which the stomach contents leak backwards from the stomach into the esophagus through the lower esophageal sphincter. Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:72)
- Fair hair (HP:0002286, a Human Phenotype Ontology term): A lesser degree of hair pigmentation than would otherwise be expected. Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:72)
- Drooling (HP:0002307, a Human Phenotype Ontology term): Habitual flow of saliva out of the mouth. Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:72)
- Polyphagia (HP:0002591, a Human Phenotype Ontology term): A neurological anomaly with gross overeating associated with an abnormally strong desire or need to eat. Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:72)
- Scoliosis (HP:0002650, a Human Phenotype Ontology term): The presence of an abnormal lateral curvature of the spine. Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:72)
- Sleep-wake cycle disturbance (HP:0006979, a Human Phenotype Ontology term): Any abnormality of an individual's circadian rhythm that affects the timing of sleeping and being awake is referred to as a sleep-wake disorder. Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:72)
- Iris hypopigmentation (HP:0007730, a Human Phenotype Ontology term): An abnormal reduction in the amount of pigmentation of the iris. Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:72)
- Floppy infant (HP:0008947, a Human Phenotype Ontology term): Floppiness/hypotonia is defined as reduced resistance to passive movement of joints. Physical examination of floppy/hypotonic infants shows head lag, lack of shoulder and elbow muscle contraction on traction response, inability to tighten the shoulder girdle muscles (or slipping through) when held under the axillae, scarf sign (when the arm is pulled to the opposite side, the arm wraps around the neck with the elbow crossing midline), hyperdorsiflexion of the feet, easy apposition of the thumb against the forearm, feet touching the cheek with ease and without discomfort, frog leg position, and inverted U sign on ventral suspension (head, arms, and legs hanging down without elbow or knee flexion and the trunk rounded in a dome shape). Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:72)
- Protruding tongue (HP:0010808, a Human Phenotype Ontology term): Tongue extending beyond the alveolar ridges or teeth at rest. Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:72)
- Abnormality of the gastrointestinal tract (HP:0011024, a Human Phenotype Ontology term): An abnormality of the gastrointestinal tract. Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:72)
- Feeding difficulties (HP:0011968, a Human Phenotype Ontology term): Impaired ability to eat related to problems gathering food and getting ready to suck, chew, or swallow it. Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:72)
- Recurrent hand flapping (HP:0100023, a Human Phenotype Ontology term): A type of repetitive behavior in which the affected individual repeatedly waves the hands and/or arms rhythmically. Evidence: TAS. Frequency: Frequent (HP:0040282, a Human Phenotype Ontology term). (ORPHA:72)
- Mandibular prognathia (HP:0000303, a Human Phenotype Ontology term): Abnormal prominence of the chin related to increased length of the mandible. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Ptosis (HP:0000508, a Human Phenotype Ontology term): The upper eyelid margin is positioned 3 mm or more lower than usual and covers the superior portion of the iris (objective); or, the upper lid margin obscures at least part of the pupil (subjective). Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Hypermetropia (HP:0000540, a Human Phenotype Ontology term): An abnormality of refraction characterized by the ability to see objects in the distance clearly, while objects nearby appear blurry. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Optic disc pallor (HP:0000543, a Human Phenotype Ontology term): A pale yellow discoloration of the optic disc (the area of the optic nerve head in the retina). The optic disc normally has a pinkish hue with a central yellowish depression. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Myopia (HP:0000545, a Human Phenotype Ontology term): An abnormality of refraction characterized by the ability to see objects nearby clearly, while objects in the distance appear blurry. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Keratoconus (HP:0000563, a Human Phenotype Ontology term): A cone-shaped deformity of the cornea characterized by the presence of corneal distortion secondary to thinning of the apex. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Nystagmus (HP:0000639, a Human Phenotype Ontology term): Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Amblyopia (HP:0000646, a Human Phenotype Ontology term): Reduced visual acuity that is uncorrectable by lenses in the absence of detectable anatomic defects in the eye or visual pathways. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Optic atrophy (HP:0000648, a Human Phenotype Ontology term): Atrophy of the optic nerve. Optic atrophy results from the death of the retinal ganglion cell axons that comprise the optic nerve and manifesting as a pale optic nerve on fundoscopy. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Widely spaced teeth (HP:0000687, a Human Phenotype Ontology term): Increased spaces (diastemata) between most of the teeth in the same dental arch. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Aggressive behavior (HP:0000718, a Human Phenotype Ontology term): 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, a Human Phenotype Ontology term). (ORPHA:72)
- Anxiety (HP:0000739, a Human Phenotype Ontology term): 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, a Human Phenotype Ontology term). (ORPHA:72)
- Reduced eye contact (HP:0000817, a Human Phenotype Ontology term): A reduced frequency or duration of eye contact. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Myoclonus (HP:0001336, a Human Phenotype Ontology term): Very brief, involuntary random muscular contractions occurring at rest, in response to sensory stimuli, or accompanying voluntary movements. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Absent speech (HP:0001344, a Human Phenotype Ontology term): Complete lack of development of speech and language abilities. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Vomiting (HP:0002013, a Human Phenotype Ontology term): Forceful ejection of the contents of the stomach through the mouth by means of a series of involuntary spasmic contractions. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Dysphagia (HP:0002015, a Human Phenotype Ontology term): Difficulty in swallowing. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Poor suck (HP:0002033, a Human Phenotype Ontology term): An inadequate sucking reflex, resulting in the difficult of newborns to be breast-fed. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Generalized myoclonic seizure (HP:0002123, a Human Phenotype Ontology term): 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: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Status epilepticus (HP:0002133, a Human Phenotype Ontology term): 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: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Inability to walk (HP:0002540, a Human Phenotype Ontology term): Incapability to ambulate. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Flat occiput (HP:0005469, a Human Phenotype Ontology term): Reduced convexity of the occiput (posterior part of skull). Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Cerebral dysmyelination (HP:0007266, a Human Phenotype Ontology term): Defective structure and function of myelin sheaths of the white matter of the brain. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Atypical absence seizure (HP:0007270, a Human Phenotype Ontology term): 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, a Human Phenotype Ontology term). (ORPHA:72)
- Pes valgus (HP:0008081, a Human Phenotype Ontology term): An outward (valgus) deviation of the calcaneus relative to the longitudinal axis of the lower leg at the talocalcaneal (subtalar) joint, such that the heel is everted. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Precocious puberty in females (HP:0010465, a Human Phenotype Ontology term): The onset of puberty before the age of 8 years in girls. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Atonic seizure (HP:0010819, a Human Phenotype Ontology term): 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: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Gastrostomy tube feeding in infancy (HP:0011471, a Human Phenotype Ontology term): Feeding problem necessitating gastrostomy tube feeding. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Delayed menarche (HP:0012569, a Human Phenotype Ontology term): First period after the age of 15 years. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Happy demeanor (HP:0040082, a Human Phenotype Ontology term): A conspicuously happy disposition, characterized by frequent smiling and laughing, which may be contextually inappropriate or unrelated to the situation. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Nasogastric tube feeding (HP:0040288, a Human Phenotype Ontology term): The condition of inability to eat normally treated by placement of a thin tube through the nose into the stomach that is then used to carry food. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Tongue thrusting (HP:0100703, a Human Phenotype Ontology term): Pressing forward of the tongue in the mouth, a retained motoric habit from infantile swallowing patterns. Evidence: TAS. Frequency: Occasional (HP:0040283, a Human Phenotype Ontology term). (ORPHA:72)
- Infantile spasms (HP:0012469, a Human Phenotype Ontology term): Infantile spasms represent a subset of "epileptic spasms". Infantile Spasms are epileptic spasms starting in the first year of life (infancy). Evidence: TAS. Frequency: Very rare (HP:0040284, a Human Phenotype Ontology term). (ORPHA:72)
These phenotypes are associated with the disease Angelman syndrome (ORPHA:72, an Orphanet rare-disease identifier).