- Microcephaly (HP:0000252): Head circumference below 2 standard deviations below the mean for age and gender. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:457351)
- Sensorineural hearing impairment (HP:0000407): A type of hearing impairment in one or both ears related to an abnormal functionality of the cochlear nerve. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:457351)
- Visual impairment (HP:0000505): Visual impairment (or vision impairment) is vision loss (of a person) to such a degree as to qualify as an additional support need through a significant limitation of visual capability resulting from either disease, trauma, or congenital or degenerative conditions that cannot be corrected by conventional means, such as refractive correction, medication, or surgery. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:457351)
- 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 frequent (HP:0040281). (ORPHA:457351)
- 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: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:457351)
- 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:457351)
- Reduced eye contact (HP:0000817): A reduced frequency or duration of eye contact. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:457351)
- 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: Frequent (HP:0040282). (ORPHA:457351)
- Spasticity (HP:0001257): A motor disorder characterized by a velocity-dependent increase in tonic stretch reflexes with increased muscle tone, exaggerated (hyperexcitable) tendon reflexes. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:457351)
- Absent speech (HP:0001344): Complete lack of development of speech and language abilities. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:457351)
- 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: Frequent (HP:0040282). (ORPHA:457351)
- 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:457351)
- 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:457351)
- Moderate intellectual disability (HP:0002342): Moderate intellectual disability (ID) is defined as a type of ID characterized by moderately sub-average adaptive functioning and intellectual functioning, with an intelligence quotient (IQ) the range of 35-49. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:457351)
- Inability to walk (HP:0002540): Incapability to ambulate. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:457351)
- Cerebral hypomyelination (HP:0006808): Reduced amount of myelin in the nervous system resulting from defective myelinogenesis in the white matter of the central nervous system. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:457351)
- Severe expressive language delay (HP:0006863): A severe delay in the acquisition of the ability to use language to communicate needs, wishes, or thoughts. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:457351)
- Floppy infant (HP:0008947): 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). (ORPHA:457351)
- Severe intellectual disability (HP:0010864): 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: Frequent (HP:0040282). (ORPHA:457351)
- Severe receptive language delay (HP:0011352): A severe delay in the acquisition of the ability to understand the speech of others. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:457351)
- Abnormal brain morphology (HP:0012443): A structural abnormality of the brain, which has as its parts the forebrain, midbrain, and hindbrain. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:457351)
- Cerebral visual impairment (HP:0100704): A form of loss of vision caused by damage to the visual cortex rather than a defect in the eye. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:457351)
- Retrognathia (HP:0000278): An abnormality in which the mandible is mislocalised posteriorly. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:457351)
- Underdeveloped nasal alae (HP:0000430): Thinned, deficient, or excessively arched ala nasi. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:457351)
- Neonatal hypotonia (HP:0001319): Muscular hypotonia (abnormally low muscle tone) manifesting in the neonatal period. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:457351)
- Thrombocytopenia (HP:0001873): A reduction in the number of circulating thrombocytes. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:457351)
- Constipation (HP:0002019): Infrequent or difficult evacuation of feces. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:457351)
- Hypoplasia of the corpus callosum (HP:0002079): Underdevelopment of the corpus callosum. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:457351)
- Cerebral cortical atrophy (HP:0002120): Atrophy of the cortex of the cerebrum. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:457351)
- Global brain atrophy (HP:0002283): Unlocalized atrophy of the brain with decreased total brain matter volume and increased ventricular size. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:457351)
- Limb hypertonia (HP:0002509). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:457351)
- 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: TAS. Frequency: Occasional (HP:0040283). (ORPHA:457351)
- Highly arched eyebrow (HP:0002553): Increased height of the central portion of the eyebrow, forming a crescent, semicircular, or inverted U shape. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:457351)
- Immunodeficiency (HP:0002721): Failure of the immune system to protect the body adequately from infection, due to the absence or insufficiency of some component process or substance. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:457351)
- Long nose (HP:0003189): Distance from nasion to subnasale more than two standard deviations above the mean, or alternatively, an apparently increased length from the nasal root to the nasal base. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:457351)
- Depressed nasal bridge (HP:0005280): Posterior positioning of the nasal root in relation to the overall facial profile for age. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:457351)
- High nonceruloplasmin-bound serum copper (HP:0010838): An increased concentration of non ceruloplasmin bound copper in the blood. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:457351)
- Broad eyebrow (HP:0011229): Regional increase in the width (height) of the eyebrow. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:457351)
- EEG with frontal sharp slow waves (HP:0011290): EEG with sharp slow waves in the frontal region. Sharp slow waves are focal sharp transient waves of a duration between 80 and 200 msec followed by a slow wave. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:457351)
- Primary microcephaly (HP:0011451): Head circumference below 2 standard deviations below the mean for age and gender at birth. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:457351)
- Brain atrophy (HP:0012444): Partial or complete wasting (loss) of brain tissue that was once present. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:457351)
- Infantile spasms (HP:0012469): Infantile spasms represent a subset of "epileptic spasms". Infantile Spasms are epileptic spasms starting in the first year of life (infancy). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:457351)
- 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: TAS. Frequency: Very rare (HP:0040284). (ORPHA:457351)
- Atrial septal defect (HP:0001631): Atrial septal defect (ASD) is a congenital abnormality of the interatrial septum that enables blood flow between the left and right atria via the interatrial septum. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:457351)
- Limb dystonia (HP:0002451): A type of dystonia (abnormally increased muscular tone causing fixed abnormal postures) that affects muscles of the limbs. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:457351)
- Scoliosis (HP:0002650): The presence of an abnormal lateral curvature of the spine. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:457351)
- Sacral hypertrichosis (HP:0004532): Excessive, increased hair growth located in the sacral region. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:457351)
- Gastrostomy tube feeding in infancy (HP:0011471): Feeding problem necessitating gastrostomy tube feeding. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:457351)
- Exodeviation (HP:0020049): A manifest or latent ocular deviation in which one or both eyes tends to deviate temporally. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:457351)
- Self-injurious behavior (HP:0100716): Self-aggression. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:457351)
These phenotypes are associated with the disease Microcephaly-intellectual disability-sensorineural hearing loss-epilepsy-abnormal muscle tone syndrome (ORPHA:457351).