Phenotypes associated with the disease Polymicrogyria with optic nerve hypoplasia (ORPHA:250972):
- Optic nerve hypoplasia (HP:0000609): Underdevelopment of the optic nerve. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:250972)
- Abnormality of the nervous system (HP:0000707): An abnormality of the nervous system. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:250972)
- 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: Very frequent (HP:0040281). (ORPHA:250972)
- Hyporeflexia (HP:0001265): Reduction of neurologic reflexes such as the knee-jerk reaction. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:250972)
- Neonatal hypotonia (HP:0001319): Muscular hypotonia (abnormally low muscle tone) manifesting in the neonatal period. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:250972)
- Absent speech (HP:0001344): Complete lack of development of speech and language abilities. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:250972)
- Polymicrogyria (HP:0002126): Polymicrogyria is a congenital malformation of the cerebral cortex characterized by abnormal cortical layering (lamination) and an excessive number of small gyri (folds). Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:250972)
- Severe global developmental delay (HP:0011344): A severe delay in the achievement of motor or mental milestones in the domains of development of a child. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:250972)
- Colpocephaly (HP:0030048): Colpocephaly is an anatomic finding in the brain manifested by occipital horns that are disproportionately enlarged in comparison with other parts of the lateral ventricles. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:250972)
- Agenesis of corpus callosum (HP:0001274): Absence of the corpus callosum as a result of the failure of the corpus callosum to develop, which can be the result of a failure in any one of the multiple steps of callosal development including cellular proliferation and migration, axonal growth or glial patterning at the midline. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:250972)
- 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: TAS. Frequency: Frequent (HP:0040282). (ORPHA:250972)
- Hypoplasia of the brainstem (HP:0002365): Underdevelopment of the brainstem. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:250972)
- Dysplastic corpus callosum (HP:0006989): Dysplasia and dysgenesis of the corpus callosum are nonspecific descriptions that imply defective development of the corpus callosum. The term dysplasia is applied when the morphology of the corpus callosum is altered as a congenital trait. For instance, the corpus callosum may be hump-shaped, kinked, or a striped corpus callosum that lacks an anatomically distinct genu and splenium. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:250972)
- 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:250972)