- 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:254780)
- Progressive neurologic deterioration (HP:0002344). Evidence: IEA. (OMIM:254780)
- Visual loss (HP:0000572): Loss of visual acuity (implying that vision was better at a certain time point in life). Otherwise the term reduced visual acuity should be used (or a subclass of that). Evidence: IEA. (OMIM:254780)
- Visual hallucination (HP:0002367): Visual perception in the absence of a visual stimulus. Evidence: IEA. (OMIM:254780)
- Cutaneous photosensitivity (HP:0000992): An increased sensitivity of the skin to light. Photosensitivity may result in a rash upon exposure to the sun (which is known as photodermatosis). Photosensitivity can be diagnosed by phototests in which light is shone on small areas of skin. Evidence: IEA. (OMIM:254780)
- Hepatic failure (HP:0001399). Evidence: IEA. (OMIM:254780)
- Gait disturbance (HP:0001288): The term gait disturbance can refer to any disruption of the ability to walk. Evidence: IEA. (OMIM:254780)
- Generalized myoclonic seizure (HP:0002123): A generalized myoclonic seizure is a type of generalized motor seizure characterized by bilateral, 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: IEA. (OMIM:254780)
- Apraxia (HP:0002186): A defect in the understanding of complex motor commands and in the execution of certain learned movements, i.e., deficits in the cognitive components of learned movements. Evidence: IEA. (OMIM:254780)
- Generalized non-motor (absence) seizure (HP:0002121): 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: IEA. (OMIM:254780)
- Psychosis (HP:0000709): A condition characterized by changes in personality and thought patterns, often accompanied by hallucinations and delusional beliefs, is known as psychosis. Evidence: IEA. (OMIM:254780)
- Lafora bodies (HP:0100318): An intraneuronal inclusion body composed of acid mucopolysaccharides. Evidence: PCS. (PMID:14663053)
- Dementia (HP:0000726): A loss of global cognitive ability of sufficient amount to interfere with normal social or occupational function. Dementia represents a loss of previously present cognitive abilities, generally in adults, and can affect memory, thinking, language, judgment, and behavior. Evidence: IEA. (OMIM:254780)
- Focal sensory seizure with visual features (HP:0011165): A seizure characterized by elementary visual hallucinations such as flashing or flickering lights/colors, or other shapes, simple patterns, scotomata, or amaurosis as its first clinical manifestation. Evidence: TAS. Frequency: 20/20. (OMIM:254780)
- 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:254780)
- Bilateral tonic-clonic seizure with focal onset (HP:0007334): A bilateral tonic-clonic seizure with focal onset is a focal-onset seizure which progresses into a bilateral tonic-clonic phase. Evidence: IEA. (OMIM:254780)
- Myoclonus (HP:0001336): Very brief, involuntary random muscular contractions occurring at rest, in response to sensory stimuli, or accompanying voluntary movements. Evidence: IEA. (OMIM:254780)
- Rapidly progressive (HP:0003678): Applies to a disease manifestation that quickly increases in scope or severity over the course of time. Evidence: TAS. (OMIM:254780)
These phenotypes are associated with the disease myoclonic epilepsy of Lafora 1 (OMIM:254780).