- 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: IEA. (OMIM:610003)
- Clumsiness (HP:0002312): Lack of physical coordination resulting in an abnormal tendency to drop items or bump into objects. Evidence: IEA. (OMIM:610003)
- Cerebral atrophy (HP:0002059): Atrophy (wasting, decrease in size of cells or tissue) affecting the cerebrum. Evidence: IEA. (OMIM:610003)
- EEG abnormality (HP:0002353): 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: IEA. (OMIM:610003)
- Cerebellar atrophy (HP:0001272): Cerebellar atrophy is defined as a cerebellum with initially normal structures, in a posterior fossa with normal size, which displays enlarged fissures (interfolial spaces) in comparison to the foliae secondary to loss of tissue. Cerebellar atrophy implies irreversible loss of tissue and result from an ongoing progressive disease until a final stage is reached or a single injury, e.g. an intoxication or infectious event. Evidence: IEA. (OMIM:610003)
- 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: IEA. (OMIM:610003)
- Increased neuronal autofluorescent lipopigment (HP:0002074): Lipofuscin, a generic term applied to autofluorescent lipopigment, is a mixture of protein and lipid that accumulates in most aging cells, particularly those involved in high lipid turnover (e.g., the adrenal medulla) or phagocytosis of other cell types (e g., the retinal pigment epithelium or RPE; macrophage). This term pertains if there is an increase in the neuronal accumulation of lipofuscin (also known as autofluorescent lipoprotein) more than expected for the age of the patient. Evidence: IEA. (OMIM:610003)
- Irritability (HP:0000737): An emotional state characterized by negative feelings of heightened frustration, annoyance, or feeling upset, often triggered by internal factors (e.g., fatigue, hunger, unfulfilled desires) or external factors (e.g., social or environmental challenges). Irritability may be unpredictable, and is accompanied by a lowered threshold for emotional reactivity and observable features (speech, facial expressions, or psychomotor activity). Evidence: TAS. (OMIM:610003)
- Autosomal recessive inheritance (HP:0000007): 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: IEA. (OMIM:610003)
- Restlessness (HP:0000711): A state of unease is characterized by diffuse motor activity or motion, which is subject to limited control, nonproductive, or disorganized behavior. Evidence: IEA. (OMIM:610003)
- Mental deterioration (HP:0001268): Loss of previously present mental abilities, generally in adults. Evidence: TAS. (OMIM:610003)
- 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: IEA. (OMIM:610003)
- Slowly progressive (HP:0003677): Applies to a disease manifestation that only slowly increases in scope or severity over the course of time. Evidence: IEA. (OMIM:610003)
- Curvilinear intracellular accumulation of autofluorescent lipopigment storage material (HP:0003205): An intracellular accumulation of autofluorescent lipopigment storage material in a curved pattern. Evidence: IEA. (OMIM:610003)
These phenotypes are associated with the disease neuronal ceroid lipofuscinosis 8 northern epilepsy variant (OMIM:610003).