- Optic atrophy (HP:0000648): 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: Frequent (HP:0040282). (ORPHA:401777)
- 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:401777)
- 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:401777)
- 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:401777)
- 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: Frequent (HP:0040282). (ORPHA:401777)
- 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: Frequent (HP:0040282). (ORPHA:401777)
- Abnormal facial shape (HP:0001999): An abnormal morphology (form) of the face or its components. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:401777)
- Hypoplasia of the corpus callosum (HP:0002079): Underdevelopment of the corpus callosum. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:401777)
- Reduced visual acuity (HP:0007663). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:401777)
- Epicanthus (HP:0000286): A fold of skin starting above the medial aspect of the upper eyelid and arching downward to cover, pass in front of and lateral to the medial canthus. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:401777)
- Hearing impairment (HP:0000365): A decreased magnitude of the sensory perception of sound. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:401777)
- Protruding ear (HP:0000411): Angle formed by the plane of the ear and the mastoid bone greater than the 97th centile for age (objective); or, outer edge of the helix more than 2 cm from the mastoid at the point of maximum distance (objective). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:401777)
- Prominent nasal bridge (HP:0000426): Anterior positioning of the nasal root in comparison to the usual positioning for age. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:401777)
- 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: Occasional (HP:0040283). (ORPHA:401777)
- Strabismus (HP:0000486): 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: Occasional (HP:0040283). (ORPHA:401777)
- Esotropia (HP:0000565): A form of strabismus with one or both eyes turned inward ('crossed') to a relatively severe degree, usually defined as 10 diopters or more. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:401777)
- Exotropia (HP:0000577): A form of strabismus with one or both eyes deviated outward. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:401777)
- Upslanted palpebral fissure (HP:0000582): The palpebral fissure inclination is more than two standard deviations above the mean for age (objective); or, the inclination of the palpebral fissure is greater than typical for age. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:401777)
- Optic nerve hypoplasia (HP:0000609): Underdevelopment of the optic nerve. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:401777)
- Amblyopia (HP:0000646): 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). (ORPHA:401777)
- Compulsive behaviors (HP:0000722): Behavior that consists of repetitive acts, characterized by the feeling that one "has to" perform them, while being aware that these acts are not in line with one's overall goal. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:401777)
- Visual field defect (HP:0001123). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:401777)
- Tapered finger (HP:0001182): The gradual reduction in girth of the finger from proximal to distal. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:401777)
- Absent speech (HP:0001344): Complete lack of development of speech and language abilities. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:401777)
- Short nasal bridge (HP:0003194): Decreased superior-inferior length of the nasal bridge, which is the saddle-shaped area that includes the nasal root and the lateral aspects of the nose. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:401777)
- 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: Occasional (HP:0040283). (ORPHA:401777)
- Optic disc hypoplasia (HP:0007766): Underdevelopment of the optic disc, that is of the optic nerve head, where ganglion cell axons exit the eye to form the optic nerve. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:401777)
- Repetitive compulsive behavior (HP:0008762). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:401777)
- Abnormal helix morphology (HP:0011039): An abnormality of the helix. The helix is the outer rim of the ear that extends from the insertion of the ear on the scalp (root) to the termination of the cartilage at the earlobe. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:401777)
- 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: Occasional (HP:0040283). (ORPHA:401777)
- Hypermetropia (HP:0000540): An abnormality of refraction characterized by the ability to see objects in the distance clearly, while objects nearby appear blurry. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:401777)
- Myopia (HP:0000545): An abnormality of refraction characterized by the ability to see objects nearby clearly, while objects in the distance appear blurry. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:401777)
- Keratoconus (HP:0000563): A cone-shaped deformity of the cornea characterized by the presence of corneal distortion secondary to thinning of the apex. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:401777)
- Nystagmus (HP:0000639): Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:401777)
- 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: Very rare (HP:0040284). (ORPHA:401777)
- Delayed skeletal maturation (HP:0002750): A decreased rate of skeletal maturation. Delayed skeletal maturation can be diagnosed on the basis of an estimation of the bone age from radiographs of specific bones in the human body. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:401777)
- Short stature (HP:0004322): A height below that which is expected according to age and gender norms. Although there is no universally accepted definition of short stature, many refer to "short stature" as height more than 2 standard deviations below the mean for age and gender (or below the 3rd percentile for age and gender dependent norms). Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:401777)
- Delayed myelination (HP:0012448): Delayed myelination. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:401777)
- Abnormal hippocampus morphology (HP:0025100): Any structural anomaly of the hippocampus,. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:401777)
These phenotypes are associated with the disease Optic atrophy-intellectual disability syndrome (ORPHA:401777).