- Bilateral tonic-clonic seizure (HP:0002069, a Human Phenotype Ontology term): 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: 11/25. (PMID:34626583)
- Narrow forehead (HP:0000341, a Human Phenotype Ontology term): 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: PCS. Frequency: 1/25. (PMID:34626583)
- Dystonia (HP:0001332, a Human Phenotype Ontology term): An abnormally increased muscular tone that causes fixed abnormal postures. There is a slow, intermittent twisting motion that leads to exaggerated turning and posture of the extremities and trunk. Evidence: PCS. Frequency: 15/25. (PMID:34626583)
- Seizure (HP:0001250, a Human Phenotype Ontology term): 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: 13/18. (PMID:34626583)
- Generalized non-motor (absence) seizure (HP:0002121, a Human Phenotype Ontology term): A generalized non-motor (absence) seizure is a type of a type of dialeptic seizure that is of electrographically generalized onset. It is a generalized seizure characterized by an interruption of activities, a blank stare, and usually the person will be unresponsive when spoken to. Any ictal motor phenomena are minor in comparison to these non-motor features. Evidence: PCS. Frequency: 3/25. (PMID:34626583)
- Hypotonia (HP:0001252, a Human Phenotype Ontology term): 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: 13/17. (PMID:34626583)
- Infantile onset (HP:0003593, a Human Phenotype Ontology term): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. (PMID:34626583)
- Myoclonic seizure (HP:0032794, a Human Phenotype Ontology term): A myoclonic seizure is a type of motor seizure characterized by sudden, brief (<100 ms) involuntary single or multiple contraction of muscles or muscle groups of variable topography (axial, proximal limb, distal). Myoclonus is less regularly repetitive and less sustained than is clonus. Evidence: PCS. Frequency: 7/25. (PMID:34626583)
- Infantile spasms (HP:0012469, a Human Phenotype Ontology term): Infantile spasms represent a subset of "epileptic spasms". Infantile Spasms are epileptic spasms starting in the first year of life (infancy). Evidence: PCS. Frequency: 4/25. (PMID:34626583)
- Cerebral visual impairment (HP:0100704, a Human Phenotype Ontology term): A form of loss of vision caused by damage to the visual cortex rather than a defect in the eye. Evidence: PCS. Frequency: 15/25. (PMID:34626583)
- Periventricular leukomalacia (HP:0006970, a Human Phenotype Ontology term): Periventricular leukomalacia is characterized by diffuse injury of deep cerebral white matter, accompanied in its most severe form by focal necrosis. The neuropathologic hallmarks of PVL are microglial activation and focal and diffuse periventricular depletion of premyelinating oligodendroglia. Evidence: PCS. (PMID:34626583)
- High palate (HP:0000218, a Human Phenotype Ontology term): Height of the palate more than 2 SD above the mean (objective) or palatal height at the level of the first permanent molar more than twice the height of the teeth (subjective). Evidence: PCS. Frequency: 1/25. (PMID:34626583)
- Intellectual disability (HP:0001249, a Human Phenotype Ontology term): 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. (PMID:34626583)
- Thick upper lip vermilion (HP:0000215, a Human Phenotype Ontology term): Height of the vermilion of the upper lip in the midline more than 2 SD above the mean. Alternatively, an apparently increased height of the vermilion of the upper lip in the frontal view (subjective). Evidence: PCS. Frequency: 1/25. (PMID:34626583)
- Microcephaly (HP:0000252, a Human Phenotype Ontology term): Head circumference below 2 standard deviations below the mean for age and gender. Evidence: PCS. Frequency: 13/25. (PMID:34626583)
- Spastic tetraplegia (HP:0002510, a Human Phenotype Ontology term): Spastic paralysis affecting all four limbs. Evidence: PCS. Frequency: 12/14. (PMID:34626583)
- Downslanted palpebral fissures (HP:0000494, a Human Phenotype Ontology term): The palpebral fissure inclination is more than two standard deviations below the mean. Evidence: PCS. Frequency: 2/25. (PMID:34626583)
- Scoliosis (HP:0002650, a Human Phenotype Ontology term): The presence of an abnormal lateral curvature of the spine. Evidence: PCS. Frequency: 7/25. (PMID:34626583)
- Hypoplasia of the corpus callosum (HP:0002079, a Human Phenotype Ontology term): Underdevelopment of the corpus callosum. Evidence: PCS. (PMID:34626583)
- Global developmental delay (HP:0001263, a Human Phenotype Ontology term): 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: 18/18. (PMID:34626583)
- Low anterior hairline (HP:0000294, a Human Phenotype Ontology term): Distance between the hairline (trichion) and the glabella (the most prominent point on the frontal bone above the root of the nose), in the midline, more than two SD below the mean. Alternatively, an apparently decreased distance between the hairline and the glabella. Evidence: PCS. Frequency: 1/25. (PMID:34626583)
- Depressed nasal bridge (HP:0005280, a Human Phenotype Ontology term): Posterior positioning of the nasal root in relation to the overall facial profile for age. Evidence: PCS. Frequency: 1/25. (PMID:34626583)
- Enlarged sylvian cistern (HP:0100952, a Human Phenotype Ontology term): An increase in size of the subarachnoid space associated with the lateral cerebral sulcus (Sylvian fissure). Evidence: PCS. (PMID:34626583)
- Telecanthus (HP:0000506, a Human Phenotype Ontology term): 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: 1/25. (PMID:34626583)
- Spastic hemiparesis (HP:0011099, a Human Phenotype Ontology term): Unilateral paresis (weakness) with spasticity of the affected muscles and increased tendon reflexes. Evidence: PCS. Frequency: 1/14. (PMID:34626583)
- Autosomal recessive inheritance (HP:0000007, a Human Phenotype Ontology term): 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 individuals with two pathogenic alleles, either homozygotes (two copies of the same mutant allele) or compound heterozygotes (whereby each copy of a gene has a distinct mutant allele). Evidence: PCS. (PMID:34626583)
- Spasticity (HP:0001257, a Human Phenotype Ontology term): A motor disorder characterized by a velocity-dependent increase in tonic stretch reflexes with increased muscle tone, exaggerated (hyperexcitable) tendon reflexes. Evidence: PCS. Frequency: 17/25. (PMID:34626583)
- Focal-onset seizure (HP:0007359, a Human Phenotype Ontology term): 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: PCS. Frequency: 4/25. (PMID:34626583)
- Micrognathia (HP:0000347, a Human Phenotype Ontology term): Developmental hypoplasia of the mandible. Evidence: PCS. Frequency: 1/25. (PMID:34626583)
These phenotypes are associated with the disease neurodevelopmental disorder with hearing loss and spasticity (OMIM:619616, an entry in Online Mendelian Inheritance in Man).