- Abnormality of neuronal migration (HP:0002269): An abnormality resulting from an anomaly of neuronal migration, i.e., of the process by which neurons travel from their origin to their final position in the brain. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:98889)
- Bilateral perisylvian polymicrogyria (HP:0032407): A type of perisylvian polymicrogyria that affects both sides of the brain. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:98889)
- 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: Frequent (HP:0040282). (ORPHA:98889)
- 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:98889)
- 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:98889)
- 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:98889)
- 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:98889)
- 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: Frequent (HP:0040282). (ORPHA:98889)
- Hyperreflexia (HP:0001347): Hyperreflexia is the presence of hyperactive stretch reflexes of the muscles. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98889)
- Flexion contracture (HP:0001371): A flexion contracture is a bent (flexed) joint that cannot be straightened actively or passively. It is thus a chronic loss of joint motion due to structural changes in muscle, tendons, ligaments, or skin that prevents normal movement of joints. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98889)
- EEG with polyspike wave complexes (HP:0002392): The presence of complexes of repetitive spikes and waves in EEG. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98889)
- 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: Frequent (HP:0040282). (ORPHA:98889)
- Distal arthrogryposis (HP:0005684): An inherited primary limb malformation disorder characterized by congenital contractures of two or more different body areas and without primary neurologic and/or muscle disease that affects limb function. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98889)
- Focal-onset seizure (HP:0007359): A focal-onset seizure is a type of seizure originating within networks limited to one hemisphere. They may be discretely localized or more widely distributed, and may originate in subcortical structures. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98889)
- 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:98889)
- EEG with central focal spikes (HP:0012014): EEG with focal sharp transient waves of a duration less than 80 msec in the central region. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98889)
- EEG with parietal focal spikes (HP:0012017): EEG with focal sharp transient waves of a duration less than 80 msec in the parietal region. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98889)
- Perisylvian predominant thick cortex pachygyria (HP:0020190): Pachygyria with cortical thickness greater than 10 mm and a perisylvian predominant severity gradient. The severity gradient is determined based on the gyral width, with gyri typically wider than 5mm over the more severely affected regions. Perisylvian predominant gradient indicates pachygyria more severe other the occipital lobes but also includes a rare perisylvian-predominant pachygyria and a temporal predominant pachygyria. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98889)
- Weakness of facial musculature (HP:0030319): Reduced strength of one or more muscles innervated by the facial nerve (the seventh cranial nerve). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98889)
- Microcephaly (HP:0000252): Head circumference below 2 standard deviations below the mean for age and gender. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
- Micrognathia (HP:0000347): Developmental hypoplasia of the mandible. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
- Hearing impairment (HP:0000365): A decreased magnitude of the sensory perception of sound. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
- Choanal atresia (HP:0000453): Absence or abnormal closure of the choana (the posterior nasal aperture). Most embryologists believe that posterior choanal atresia results from a failure of rupture between the 35th and 38th day of fetal life of the partition which separates the bucconasal or buccopharyngeal membranes. The resultant choanal atresia may be unilateral or bilateral, bony or membranous, complete or incomplete. In over 90 per cent of cases the obstruction is bony, while in the remainder it is membranous. The bony type of atresia is commonly located 1-2 mm. anterior to the posterior edge of the hard palate, and the osseous septum varies in thickness from 1 to 10 mm. In the membranous form of choanal atresia the obstruction usually occurs further posteriorly. In approximately one third of cases the atresia is bilateral. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
- Nystagmus (HP:0000639): Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
- Pectus excavatum (HP:0000767): A defect of the chest wall characterized by a depression of the sternum, giving the chest ("pectus") a caved-in ("excavatum") appearance. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
- Dysarthria (HP:0001260): Dysarthric speech is a general description referring to a neurological speech disorder characterized by poor articulation. Depending on the involved neurological structures, dysarthria may be further classified as spastic, flaccid, ataxic, hyperkinetic and hypokinetic, or mixed. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
- Dysmetria (HP:0001310): A type of ataxia characterized by the inability to carry out movements with the correct range and motion across the plane of more than one joint related to incorrect estimation of the distances required for targeted movements. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
- Cerebellar vermis hypoplasia (HP:0001320): Underdevelopment of the vermis of cerebellum. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
- Facial diplegia (HP:0001349): Facial diplegia refers to bilateral facial palsy (bilateral facial palsy is much rarer than unilateral facial palsy). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
- Intrauterine growth retardation (HP:0001511): An abnormal restriction of fetal growth with fetal weight below the tenth percentile for gestational age. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
- Dysphagia (HP:0002015): Difficulty in swallowing. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
- 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:98889)
- Lower limb spasticity (HP:0002061): Spasticity (velocity-dependent increase in tonic stretch reflexes with increased muscle tone and hyperexcitable tendon reflexes) in the muscles of the lower limbs, hips, and pelvis. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
- Apnea (HP:0002104): Lack of breathing with no movement of the respiratory muscles and no exchange of air in the lungs. This term refers to a disposition to have recurrent episodes of apnea rather than to a single event. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
- Drooling (HP:0002307): Habitual flow of saliva out of the mouth. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
- Paraparesis (HP:0002385): Weakness or partial paralysis in the lower limbs. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
- Limb hypertonia (HP:0002509). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
- Spastic tetraplegia (HP:0002510): Spastic paralysis affecting all four limbs. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
- Aspiration (HP:0002835): Inspiration of a foreign object into the airway. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
- Pseudobulbar paralysis (HP:0007024): Bilateral impairment of the function of the cranial nerves 9-12, which control musculature involved in eating, swallowing, and speech. Pseudobulbar paralysis is characterized clinically by dysarthria, dysphonia, and dysphagia with bifacial paralysis, and may be accompanied by Pseudobulbar behavioral symptoms such as enforced crying and laughing. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
- Cerebellar dysplasia (HP:0007033): Cerebellar dysplasia (abnormal growth or development) is defined by abnormal cerebellar foliation, white matter arborization, and gray-white matter junction. Cerebellar dysplasia is a neuroimaging finding that describes abnormalities of both the cerebellar cortex and white matter and is associated with variable neurodevelopmental outcome. Dysplasia may globally involve the cerebellum or affect only one cerebellar hemisphere. In addition, cerebellar dysplasia may be associated with cortical/subcortical cysts. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
- Oromotor apraxia (HP:0007301): Oral-motor apraxia is the inability to volitionally sequence oral movements of the speech structure for nonspeech tasks in the absence of neuromuscular deficits such as paralysis or muscle weakness. Oral-motor apraxia is diagnosed when, despite intact sensory motor function an individual is unable to use these effector systems under voluntary control. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
- Protruding tongue (HP:0010808): Tongue extending beyond the alveolar ridges or teeth at rest. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
- Focal sensory seizure (HP:0011157): A focal sensory seizure is a type seizure beginning with a subjective sensation. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
- Ectopic posterior pituitary (HP:0011755): An abnormal anatomical location of the posterior lobe of the hypophysis, also known as the neurohypophysis. The posterior pituitary is normally present in the dorsal portion of the sella turcica, but when ectopic is usually near the median eminence. This defect is likely to be due to abnormal migration during embryogenesis. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
- 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: Occasional (HP:0040283). (ORPHA:98889)
- EEG with frontal focal spikes (HP:0012015): EEG with focal sharp transient waves of a duration less than 80 msec in the frontal region. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
- 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:98889)
- Abnormality of masticatory muscle (HP:0410011): Any abnormality of the masticatory muscle. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:98889)
These phenotypes are associated with the disease Bilateral perisylvian polymicrogyria (ORPHA:98889).