- 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:261652)
- 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:261652)
- Abnormal facial shape (HP:0001999): An abnormal morphology (form) of the face or its components. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:261652)
- Abnormality of the genital system (HP:0000078): An abnormality of the genital system. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:261652)
- Atypical behavior (HP:0000708): 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: Frequent (HP:0040282). (ORPHA:261652)
- Overgrowth (HP:0001548): Excessive postnatal growth which may comprise increased weight, increased length, and/or increased head circumference. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:261652)
- Abnormal heart morphology (HP:0001627): Any structural anomaly of the heart. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:261652)
- Recurrent infections (HP:0002719): Increased susceptibility to infections as manifested by repeated bouts of infection. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:261652)
- Brain imaging abnormality (HP:0410263): An anomaly of metabolism or structure of the brain identified by imaging. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:261652)
- Inguinal hernia (HP:0000023): Protrusion of the contents of the abdominal cavity through the inguinal canal. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:261652)
- Vesicoureteral reflux (HP:0000076): Abnormal (retrograde) movement of urine from the bladder into ureters or kidneys related to inadequacy of the valvular mechanism at the ureterovesicular junction or other causes. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:261652)
- Abnormality of the kidney (HP:0000077): An abnormality of the kidney. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:261652)
- Thick lower lip vermilion (HP:0000179): Increased thickness of the lower lip, leading to a prominent appearance of the lower lip. The height of the vermilion of the lower lip in the midline is more than 2 SD above the mean. Alternatively, an apparently increased height of the vermilion of the lower lip in the frontal view (subjective). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:261652)
- Microcephaly (HP:0000252): Head circumference below 2 standard deviations below the mean for age and gender. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:261652)
- Hearing impairment (HP:0000365): A decreased magnitude of the sensory perception of sound. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:261652)
- 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:261652)
- Delayed speech and language development (HP:0000750): A degree of language development that is significantly below the norm for a child of a specified age. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:261652)
- 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: Occasional (HP:0040283). (ORPHA:261652)
- Motor delay (HP:0001270): A type of Developmental delay characterized by a delay in acquiring motor skills. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:261652)
- Cerebellar hypoplasia (HP:0001321): Cerebellar hypoplasia is a descriptive term implying a cerebellum with a reduced volume, but a normal shape and is stable over time. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:261652)
- Failure to thrive (HP:0001508): Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:261652)
- Large for gestational age (HP:0001520): The term large for gestational age applies to babies whose birth weight lies above the 90th percentile for that gestational age. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:261652)
- 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: Occasional (HP:0040283). (ORPHA:261652)
- Hypoplasia of the corpus callosum (HP:0002079): Underdevelopment of the corpus callosum. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:261652)
- Ventriculomegaly (HP:0002119): An increase in size of the ventricular system of the brain. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:261652)
- Delayed gross motor development (HP:0002194): A type of motor delay characterized by a delay in acquiring the ability to control the large muscles of the body for walking, running, sitting, and crawling. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:261652)
- Language impairment (HP:0002463): Language impairment is a deficit in comprehension or production of language that includes reduced vocabulary, limited sentence structure, or impairments in written or spoken communication. Language abilities are substantially and quantifiably below age expectations. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:261652)
- Abnormal cerebral white matter morphology (HP:0002500): An abnormality of the cerebral white matter. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:261652)
- 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: Occasional (HP:0040283). (ORPHA:261652)
- 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: Occasional (HP:0040283). (ORPHA:261652)
- Uplifted earlobe (HP:0009909): An abnormal orientation of the earlobes such that they point out- and upward. That is, the lateral surface of ear lobe faces superiorly. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:261652)
- Moderate receptive language delay (HP:0011351): A moderate delay in the acquisition of the ability to understand the speech of others. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:261652)
- Midface retrusion (HP:0011800): Posterior positions and/or vertical shortening of the infraorbital and perialar regions, or increased concavity of the face and/or reduced nasolabial angle. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:261652)
- Abnormality of the musculoskeletal system (HP:0033127): An anomaly of the musculoskeletal system, which consists of the bones of the skeleton, muscles, cartilage, tendons, ligaments, joints, and other connective tissue. The musculoskeletal system supports the weight of the body, maintains body position and produces movements of the body or of parts of the body. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:261652)
- Self-injurious behavior (HP:0100716): Self-aggression. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:261652)
- Abnormal shape of the palpebral fissure (HP:0200005): The presence of an abnormal shape of the palpebral fissure. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:261652)
- Abnormality of the dentition (HP:0000164): Any abnormality of the teeth. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:261652)
- Brachycephaly (HP:0000248): An abnormality of skull shape characterized by a decreased anterior-posterior diameter. That is, a cephalic index greater than 81%. Alternatively, an apparently shortened anteroposterior dimension (length) of the head compared to width. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:261652)
- Developmental cataract (HP:0000519): A cataract that occurs congenitally as the result of a developmental defect, in contrast to the majority of cataracts that occur in adulthood as the result of degenerative changes of the lens. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:261652)
- 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:261652)
- Natal tooth (HP:0000695): A tooth present at birth or erupting within the first month of life. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:261652)
- Precocious puberty (HP:0000826): The onset of secondary sexual characteristics before a normal age. Although it is difficult to define normal age ranges because of the marked variation with which puberty begins in normal children, precocious puberty can be defined as the onset of puberty before the age of 8 years in girls or 9 years in boys. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:261652)
- Hyperextensible skin (HP:0000974): A condition in which the skin can be stretched beyond normal, and then returns to its initial position. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:261652)
- Tapered finger (HP:0001182): The gradual reduction in girth of the finger from proximal to distal. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:261652)
- 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 rare (HP:0040284). (ORPHA:261652)
- Plagiocephaly (HP:0001357): Asymmetric head shape, which is usually a combination of unilateral occipital flattening with ipsilateral frontal prominence, leading to rhomboid cranial shape. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:261652)
- Umbilical hernia (HP:0001537): Protrusion of abdominal contents through a defect in the abdominal wall musculature around the umbilicus. Skin and subcutaneous tissue overlie the defect. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:261652)
- Anal atresia (HP:0002023): Congenital absence of the anus, i.e., the opening at the bottom end of the intestinal tract. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:261652)
- Gliosis (HP:0002171): Gliosis is the focal proliferation of glial cells in the central nervous system. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:261652)
- Tracheomalacia (HP:0002779). Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:261652)
These phenotypes are associated with the disease Kleefstra syndrome due to a point mutation (ORPHA:261652).