Phenotypes associated with the disease developmental and epileptic encephalopathy 120 (OMIM:621468, an entry in Online Mendelian Inheritance in Man):
- 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: 1/1. (PMID:38149472)
- Moderate intellectual disability (HP:0002342, a Human Phenotype Ontology term): 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: 3/6. (PMID:41133935)
- Delayed CNS myelination (HP:0002188, a Human Phenotype Ontology term): Delayed myelination in the central nervous system. Evidence: PCS. Frequency: 1/1. (PMID:41133935)
- Mild intellectual disability (HP:0001256, a Human Phenotype Ontology term): Mild intellectual disability (ID) is defined as a type of ID characterized by mildly sub-average adaptive functioning and intellectual functioning, with an intelligence quotient (IQ) the range of 50-69. Evidence: PCS. Frequency: 1/6. (PMID:41133935)
- Dysmetria (HP:0001310, a Human Phenotype Ontology term): 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: PCS. Frequency: 1/1. (PMID:41133935)
- Pituitary gland cyst (HP:0410278, a Human Phenotype Ontology term): A fluid-filled sacs that develop on or near the pituitary gland. Evidence: PCS. Frequency: 1/6. (PMID:41133935)
- Focal impaired awareness seizure (HP:0002384, a Human Phenotype Ontology term): 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:41133935)
- 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: 2/3. (PMID:41133935)
- Sleep disturbance (HP:0002360, a Human Phenotype Ontology term): An abnormal pattern in the quality, quantity, or characteristics of sleep. Evidence: PCS. Frequency: 1/1. (PMID:41133935)
- 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. Frequency: 4/7. (PMID:41133935;PMID:38149472)
- 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: 3/3. (PMID:41133935;PMID:38149472)
- Agyria (HP:0031882, a Human Phenotype Ontology term): A congenital abnormality of the cerebral hemisphere characterized by lack of gyrations (convolutions) of the cerebral cortex. Agyria is defined as cortical regions lacking gyration with sulci great than 3 cm apart and cerebral cortex thicker than 5 mm. Evidence: PCS. Frequency: 1/1. (PMID:38149472)
- Motor delay (HP:0001270, a Human Phenotype Ontology term): A type of Developmental delay characterized by a delay in acquiring motor skills. Evidence: PCS. Frequency: 4/4. (PMID:41133935;PMID:38149472)
- Eyelid myoclonia seizure (HP:0032678, a Human Phenotype Ontology term): An eyelid myoclonia seizure is a type of generalized myoclonic seizure which may or may not be associated with loss of awareness. Evidence: PCS. Frequency: 1/1. (PMID:41133935)
- Severe intellectual disability (HP:0010864, a Human Phenotype Ontology term): Severe intellectual disability (ID) is defined as a type of ID characterized by severely sub-average adaptive functioning and intellectual functioning, with an intelligence quotient (IQ) the range of 20-34. Evidence: PCS. Frequency: 2/6. (PMID:41133935)
- Childhood onset (HP:0011463, a Human Phenotype Ontology term): Onset of disease at the age of between 1 and 5 years. Evidence: PCS. Frequency: 3/6. (PMID:41133935)
- Reduced eye contact (HP:0000817, a Human Phenotype Ontology term): A reduced frequency or duration of eye contact. Evidence: PCS. Frequency: 1/5. (PMID:41133935)
- Aggressive behavior (HP:0000718, a Human Phenotype Ontology term): 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: 1/5. (PMID:41133935)
- Chronic constipation (HP:0012450, a Human Phenotype Ontology term): Constipation for longer than three months with fewer than 3 bowel movements per week, straining, lumpy or hard stools, and a sensation of anorectal obstruction or incomplete defecation. Evidence: PCS. Frequency: 1/1. (PMID:41133935)
- Ventriculomegaly (HP:0002119, a Human Phenotype Ontology term): An increase in size of the ventricular system of the brain. Evidence: PCS. Frequency: 1/1. (PMID:38149472)
- Hyperactivity (HP:0000752, a Human Phenotype Ontology term): Hyperactivity is a condition characterized by constant and unusually high levels of activity, even in situations where it is deemed inappropriate. Evidence: PCS. Frequency: 1/6. (PMID:41133935)
- Pachygyria (HP:0001302, a Human Phenotype Ontology term): Pachygyria is a malformation of cortical development with abnormally wide gyri with sulci 1,5-3 cm apart and abnormally thick cortex measuring more than 5 mm (radiological definition). See also neuropathological definitions for 2-, 3-, and 4-layered lissencephaly. Evidence: PCS. Frequency: 1/1. (PMID:38149472)
- Microcephaly (HP:0000252, a Human Phenotype Ontology term): Head circumference below 2 standard deviations below the mean for age and gender. Evidence: PCS. Frequency: 0/6. (PMID:41133935)
- Absent speech (HP:0001344, a Human Phenotype Ontology term): Complete lack of development of speech and language abilities. Evidence: PCS. Frequency: 4/6. (PMID:41133935)
- EEG abnormality (HP:0002353, a Human Phenotype Ontology term): Abnormality observed by electroencephalogram (EEG), which is used to record of the brain's spontaneous electrical activity from multiple electrodes placed on the scalp. Evidence: PCS. Frequency: 6/6. (PMID:41133935)
- Delayed speech and language development (HP:0000750, a Human Phenotype Ontology term): A degree of language development that is significantly below the norm for a child of a specified age. Evidence: PCS. Frequency: 3/3. (PMID:41133935;PMID:38149472)
- Delayed ability to walk (HP:0031936, a Human Phenotype Ontology term): 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: 3/6. (PMID:41133935)
- Developmental regression (HP:0002376, a Human Phenotype Ontology term): Loss of developmental skills, as manifested by loss of developmental milestones. Evidence: PCS. Frequency: 1/6. (PMID:41133935)
- Atonic seizure (HP:0010819, a Human Phenotype Ontology term): Atonic seizure is a type of motor seizure characterized by a sudden loss or diminution of muscle tone without apparent preceding myoclonic or tonic event lasting about 1 to 2 seconds, involving head, trunk, jaw, or limb musculature. Evidence: PCS. Frequency: 2/2. (PMID:41133935)
- 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: 6/6. (PMID:41133935)
- Bilateral tonic-clonic seizure with generalized onset (HP:0025190, a Human Phenotype Ontology term): A bilateral tonic-clonic seizure with generalized onset is a type of bilateral tonic-clonic seizure characterized by generalized onset; these seizures rapidly engage networks in both hemispheres at the start of the seizure. Evidence: PCS. Frequency: 4/4. (PMID:41133935)
- Abnormal CNS myelination (HP:0011400, a Human Phenotype Ontology term): An abnormality of myelination of nerves in the central nervous system. Evidence: PCS. Frequency: 0/5. (PMID:41133935)
- Typical absence seizure (HP:0011147, a Human Phenotype Ontology term): A typical absence seizure is a type of generalized non-motor (absence) seizure characterized by its sudden onset, interruption of ongoing activities, a blank stare, possibly a brief upward deviation of the eyes. Usually the patient will be unresponsive when spoken to. Duration is a few seconds to half a minute with very rapid recovery. Although not always available, an EEG would usually show 3 Hz generalized epileptiform discharges during the event. Evidence: PCS. Frequency: 3/3. (PMID:41133935;PMID:38149472)
- Severe global developmental delay (HP:0011344, a Human Phenotype Ontology term): A severe delay in the achievement of motor or mental milestones in the domains of development of a child. Evidence: PCS. Frequency: 1/1. (PMID:38149472)
- Abnormal social behavior (HP:0012433, a Human Phenotype Ontology term): An abnormality of actions or reactions of a person exhibited during social interactions with other individuals. Evidence: PCS. Frequency: 1/4. (PMID:41133935)
- Epileptic spasm (HP:0011097, a Human Phenotype Ontology term): A sudden flexion, extension, or mixed extension-flexion of predominantly proximal and truncal muscles that is usually more sustained than a myoclonic movement but not as sustained as a tonic seizure. Limited forms may occur: Grimacing, head nodding, or subtle eye movements. Epileptic spasms frequently occur in clusters. Infantile spasms are the best known form, but spasms can occur at all ages. Evidence: PCS. Frequency: 2/2. (PMID:41133935;PMID:38149472)
- Atypical absence seizure (HP:0007270, a Human Phenotype Ontology term): An atypical absence seizure is a type of generalized non-motor (absence) seizure characterized by interruption of ongoing activities and reduced responsiveness. In comparison to a typical absence seizure, changes in tone may be more pronounced, onset and/or cessation may be less abrupt, and the duration of the ictus and post-ictal recovery may be longer. Although not always available, an EEG often demonstrates slow (<3 Hz), irregular, generalized spike-wave activity. Evidence: PCS. Frequency: 1/1. (PMID:41133935)
- EEG with generalized polyspikes (HP:0012001, a Human Phenotype Ontology term): EEG with repetitive generalized sharp transient waves of a duration less than 80 msec. Evidence: PCS. Frequency: 1/1. (PMID:38149472)
- Reduced cerebral white matter volume (HP:0034295, a Human Phenotype Ontology term): An abnormally low volume of the white matter of the brain. Evidence: PCS. Frequency: 1/1. (PMID:38149472)
- Autistic behavior (HP:0000729, a Human Phenotype Ontology term): 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: 1/6. (PMID:41133935)
- Tonic seizure (HP:0032792, a Human Phenotype Ontology term): A tonic seizure is a type of motor seizure characterized by unilateral or bilateral limb stiffening or elevation, often with neck stiffening. Evidence: PCS. Frequency: 1/1. (PMID:38149472)
- 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: 2/2. (PMID:41133935;PMID:38149472)
- Autosomal dominant inheritance (HP:0000006, 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 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:38149472)