- 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: PCS. Frequency: 1/1. (PMID:27620904)
- 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: PCS. Frequency: 1/1. (PMID:30213762)
- 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: PCS. Frequency: 2/2. (PMID:30213762;PMID:25356899)
- Globus pallidus calcification (HP:0031627): Pathological deposition of calcium salts in the globus pallidus. Evidence: PCS. Frequency: 1/1. (PMID:30213762)
- 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: PCS. Frequency: 4/26. (PMID:34930816)
- 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: PCS. Frequency: 14/29. (PMID:25356899;PMID:34930816)
- Focal impaired awareness seizure (HP:0002384): Focal impaired awareness seizure (or focal seizure with impaired or lost awareness) is a type of focal-onset seizure characterized by some degree (which may be partial) of impairment of the person's awareness of themselves or their surroundings at any point during the seizure. Evidence: PCS. Frequency: 1/1. (PMID:30213762)
- 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: PCS. Frequency: 15/20. (PMID:30213762;PMID:27620904;PMID:34930816)
- Sleep disturbance (HP:0002360): An abnormal pattern in the quality, quantity, or characteristics of sleep. Evidence: PCS. Frequency: 18/23. (PMID:27620904;PMID:34930816)
- Short nose (HP:0003196): Distance from nasion to subnasale more than two standard deviations below the mean, or alternatively, an apparently decreased length from the nasal root to the nasal tip. Evidence: PCS. (PMID:34930816)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. Frequency: 1/1. (PMID:30213762)
- 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: PCS. Frequency: 3/23. (PMID:34930816)
- Motor delay (HP:0001270): A type of Developmental delay characterized by a delay in acquiring motor skills. Evidence: PCS. Frequency: 28/30. (PMID:34930816)
- 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: PCS. Frequency: 11/24. (PMID:34930816)
- Anxiety (HP:0000739): 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: PCS. Frequency: 7/8. (PMID:34930816)
- 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: PCS. Frequency: 1/1. (PMID:27620904)
- Bulbous nose (HP:0000414): Increased volume and globular shape of the anteroinferior aspect of the nose. Evidence: PCS. Frequency: 1/1. (PMID:30213762)
- Thin upper lip vermilion (HP:0000219): Height of the vermilion of the upper lip in the midline more than 2 SD below the mean. Alternatively, an apparently reduced height of the vermilion of the upper lip in the frontal view (subjective). Evidence: PCS. (PMID:34930816)
- Hyperactivity (HP:0000752): Hyperactivity is a condition characterized by constant and unusually high levels of activity, even in situations where it is deemed inappropriate. Evidence: PCS. Frequency: 1/1. (PMID:27620904)
- Round face (HP:0000311): The facial appearance is more circular than usual as viewed from the front. Evidence: PCS. Frequency: 1/1. (PMID:30213762)
- 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: PCS. Frequency: 1/1. (PMID:27620904)
- Mild short stature (HP:0003502): A mild degree of short stature, more than -2 SD but not more than -3 SD from mean corrected for age and sex. Evidence: PCS. Frequency: 1/1. (PMID:30213762)
- Downslanted palpebral fissures (HP:0000494): The palpebral fissure inclination is more than two standard deviations below the mean. Evidence: PCS. Frequency: 1/1. (PMID:30213762)
- 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: PCS. Frequency: 32/32. (PMID:25356899;PMID:27620904;PMID:34930816)
- Status epilepticus (HP:0002133): 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: PCS. Frequency: 1/1. (PMID:25356899)
- Wide nasal bridge (HP:0000431): Increased breadth of the nasal bridge (and with it, the nasal root). Evidence: PCS. Frequency: 1/1. (PMID:30213762)
- Delayed ability to walk (HP:0031936): A failure to achieve the ability to walk at an appropriate developmental stage. Most children learn to walk in a series of stages, and learn to walk short distances independently between 12 and 15 months. Evidence: PCS. Frequency: 1/1. (PMID:25356899)
- Febrile seizure (within the age range of 3 months to 6 years) (HP:0002373): A febrile seizure is any type of seizure (most often a generalized tonic-clonic seizure) occurring with fever (at least 38 degrees Celsius) but in the absence of central nervous system infection, severe metabolic disturbance or other alternative precipitant in children between the ages of 3 months and 6 years. Evidence: PCS. Frequency: 1/1. (PMID:30213762)
- Feeding difficulties (HP:0011968): Impaired ability to eat related to problems gathering food and getting ready to suck, chew, or swallow it. Evidence: PCS. Frequency: 10/23. (PMID:34930816)
- 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: PCS. Frequency: 34/34. (PMID:30213762;PMID:23020937;PMID:27620904;PMID:34930816)
- Telecanthus (HP:0000506): Distance between the inner canthi more than two standard deviations above the mean (objective); or, apparently increased distance between the inner canthi. Evidence: PCS. Frequency: 1/1. (PMID:30213762)
- 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: PCS. Frequency: 24/30. (PMID:34930816)
- High forehead (HP:0000348): An abnormally increased height of the forehead. Evidence: PCS. (PMID:34930816)
- Almond-shaped palpebral fissure (HP:0007874): A shape created by an acute downward arching of the upper eyelid and upward arching of the lower eyelid, toward the medial canthus, which gives the outline of the palpebral fissures the configuration of an almond. Thus, the maximum distance between the fissures is offset from, and medial to, the center point. Evidence: PCS. (PMID:34930816)
- Macrotia (HP:0000400): Median longitudinal ear length greater than two standard deviations above the mean and median ear width greater than two standard deviations above the mean (objective); or, apparent increase in length and width of the pinna (subjective). Evidence: PCS. Frequency: 1/1. (PMID:27620904)
- 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: PCS. Frequency: 15/22. (PMID:34930816)
- Autosomal dominant inheritance (HP:0000006): A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in heterozygotes. In the context of medical genetics, an autosomal dominant disorder is caused when a single copy of the mutant allele is present. Males and females are affected equally, and can both transmit the disorder with a risk of 50% for each child of inheriting the mutant allele. Evidence: PCS. (PMID:23020937)
These phenotypes are associated with the disease neurodevelopmental disorder with language delay and behavioral abnormalities, with or without seizures (OMIM:620292).