- Wide mouth (HP:0000154): 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: Very frequent (HP:0040281). (ORPHA:2896)
- Abnormal palate morphology (HP:0000174): Any abnormality of the palate, i.e., of roof of the mouth. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- Microcephaly (HP:0000252): Head circumference below 2 standard deviations below the mean for age and gender. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- Coarse facial features (HP:0000280): Absence of fine and sharp appearance of brows, nose, lips, mouth, and chin, usually because of rounded and heavy features or thickened skin with or without thickening of subcutaneous and bony tissues. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- Full cheeks (HP:0000293): Increased prominence or roundness of soft tissues between zygomata and mandible. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- Short philtrum (HP:0000322): Distance between nasal base and midline upper lip vermilion border more than 2 SD below the mean. Alternatively, an apparently decreased distance between nasal base and midline upper lip vermilion border. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- Narrow forehead (HP:0000341): Width of the forehead or distance between the frontotemporales is more than two standard deviations below the mean (objective); or apparently narrow intertemporal region (subjective). Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- Thickened helices (HP:0000391): Increased thickness of the helix of the ear. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- Prominent nasal bridge (HP:0000426): Anterior positioning of the nasal root in comparison to the usual positioning for age. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- 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: Very frequent (HP:0040281). (ORPHA:2896)
- Short neck (HP:0000470): Diminished length of the neck. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- Astigmatism (HP:0000483): A type of refraction error associated with abnormal curvatures on the anterior and/or posterior surface of the cornea. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- Deeply set eye (HP:0000490): An eye that is more deeply recessed into the plane of the face than is typical. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- 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 frequent (HP:0040281). (ORPHA:2896)
- 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: Very frequent (HP:0040281). (ORPHA:2896)
- Tooth malposition (HP:0000692): Abnormal alignment, positioning, or spacing of the teeth, i.e., misaligned teeth. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- Single transverse palmar crease (HP:0000954): The distal and proximal transverse palmar creases are merged into a single transverse palmar crease. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- Tapered finger (HP:0001182): The gradual reduction in girth of the finger from proximal to distal. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- 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: Very frequent (HP:0040281). (ORPHA:2896)
- Ataxia (HP:0001251): 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). (ORPHA:2896)
- 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: Very frequent (HP:0040281). (ORPHA:2896)
- 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:2896)
- Specific learning disability (HP:0001328): Impairment of certain skills such as reading or writing, coordination, self-control, or attention that interfere with the ability to learn. The impairment is not related to a global deficiency of intelligence. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- Failure to thrive (HP:0001508): Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- Growth delay (HP:0001510): A deficiency or slowing down of growth pre- and postnatally. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- Pes planus (HP:0001763): A foot where the longitudinal arch of the foot is in contact with the ground or floor when the individual is standing; or, in a patient lying supine, a foot where the arch is in contact with the surface of a flat board pressed against the sole of the foot by the examiner with a pressure similar to that expected from weight bearing; or, the height of the arch is reduced. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- Constipation (HP:0002019): Infrequent or difficult evacuation of feces. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- Gastroesophageal reflux (HP:0002020): A condition in which the stomach contents leak backwards from the stomach into the esophagus through the lower esophageal sphincter. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- Hiatus hernia (HP:0002036): The presence of a hernia in which the upper part of the stomach, i.e., mainly the gastric cardia protrudes through the diaphragmatic esophageal hiatus. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- 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: Very frequent (HP:0040281). (ORPHA:2896)
- 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: Very frequent (HP:0040281). (ORPHA:2896)
- Sleep disturbance (HP:0002360): An abnormal pattern in the quality, quantity, or characteristics of sleep. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- 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:2896)
- Failure of eruption of permanent teeth (HP:0006352): Lack of tooth eruption of the secondary dentition. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- Pes valgus (HP:0008081): 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: Very frequent (HP:0040281). (ORPHA:2896)
- Echolalia (HP:0010529): Echolalia is the automatic imitative repetition of sounds, words, or phrases in the absence of explicit awareness. The repeated words or phrases are typically odd or used in a non-social manner. These can be words or phrases that the affected individual has heard or invented. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- Short metatarsal (HP:0010743): Diminished length of a metatarsal bone, with resultant proximal displacement of the associated toe. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- 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: Very frequent (HP:0040281). (ORPHA:2896)
- Broad fingertip (HP:0011300): Increased width of the distal segment of a finger. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- Overhanging nasal tip (HP:0011833): Positioning of the nasal tip inferior to the nasal base. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- Feeding difficulties (HP:0011968): Impaired ability to eat related to problems gathering food and getting ready to suck, chew, or swallow it. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- Thick vermilion border (HP:0012471): Increased width of the skin of vermilion border region of upper lip. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- Finger clinodactyly (HP:0040019). Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- Esophagitis (HP:0100633): Inflammation of the esophagus. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- Small hand (HP:0200055): Disproportionately small hand. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:2896)
- Triangular nasal tip (HP:0000451). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:2896)
- 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: Frequent (HP:0040282). (ORPHA:2896)
- Acrocyanosis (HP:0001063): Bluish discoloration of the skin of the hands or feet. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:2896)
- 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:2896)
- Absent speech (HP:0001344): Complete lack of development of speech and language abilities. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:2896)
- Narrow foot (HP:0001786): A foot for which the measured width is below the 5th centile for age; or, a foot that appears disproportionately narrow for its length. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:2896)
- 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: Frequent (HP:0040282). (ORPHA:2896)
- Small cerebral cortex (HP:0002472): Reduced size of the cerebral cortex. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:2896)
- Abnormal pattern of respiration (HP:0002793): An anomaly of the rhythm or depth of breathing. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:2896)
- Hyperventilation (HP:0002883): Hyperventilation refers to an increased pulmonary ventilation rate that is faster than necessary for the exchange of gases. Hyperventilation can result from increased frequency of breathing, an increased tidal volume, or both, and leads to an excess intake of oxygen and the blowing off of carbon dioxide. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:2896)
- Aplasia/Hypoplasia of the corpus callosum (HP:0007370): Absence or underdevelopment of the corpus callosum. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:2896)
- Sleep apnea (HP:0010535): An intermittent cessation of airflow at the mouth and nose during sleep is known as sleep apnea. Apneas that last at least 10 seconds are considered significant, but individuals with sleep apnea may experience apneas lasting from 20 seconds up to 2 or 3 minutes. Patients may have up to 15 events per hour of sleep. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:2896)
- Cryptorchidism (HP:0000028): Testis in inguinal canal. That is, absence of one or both testes from the scrotum owing to failure of the testis or testes to descend through the inguinal canal to the scrotum. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:2896)
- Micropenis (HP:0000054): Abnormally small penis. At birth, the normal penis is about 3 cm (stretched length from pubic tubercle to tip of penis) with micropenis less than 2.0-2.5 cm. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:2896)
- 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:2896)
- 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: Occasional (HP:0040283). (ORPHA:2896)
- Hypopigmented skin patches (HP:0001053). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:2896)
- Supernumerary nipple (HP:0002558): Presence of more than two nipples. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:2896)
- Scoliosis (HP:0002650): The presence of an abnormal lateral curvature of the spine. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:2896)
- Postnatal growth retardation (HP:0008897): Slow or limited growth after birth. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:2896)
- Happy demeanor (HP:0040082): 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). (ORPHA:2896)
- Self-injurious behavior (HP:0100716): Self-aggression. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:2896)
- Aganglionic megacolon (HP:0002251): An abnormality resulting from a lack of intestinal ganglion cells (i.e., an aganglionic section of bowel) that results in bowel obstruction with enlargement of the colon. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:2896)
- Hodgkin lymphoma (HP:0012189): A type of lymphoma characterized microscopically by multinucleated Reed-Sternberg cells. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:2896)
These phenotypes are associated with the disease Pitt-Hopkins syndrome (ORPHA:2896).