- Hemiplegia (HP:0002301): Paralysis (complete loss of muscle function) in the arm, leg, and in some cases the face on one side of the body. Evidence: IEA. (OMIM:609634)
- Juvenile onset (HP:0003621): Onset of signs or symptoms of disease between the age of 5 and 15 years. Evidence: PCS. Frequency: 16/17. (PMID:16054936)
- 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: IEA. (OMIM:609634)
- Migraine with aura (HP:0002077): A type of migraine in which there is an aura characterized by focal neurological phenomena that usually proceed, but may accompany or occur in the absence of, the headache. The symptoms of an aura may include fully reversible visual, sensory, and speech symptoms but not motor weakness. Visual symptoms may include flickering lights, spots and lines and/or loss of vision and/or unilateral sensory symptoms such as paresthesias or numbness. At least one of the symptoms of an aura develops gradually over 5 or more minutes and/or different symptoms occur in succession. Evidence: IEA. Frequency: 18/18. (OMIM:609634)
- Young adult onset (HP:0011462): Onset of disease at the age of between 16 and 40 years. Evidence: PCS. Frequency: 1/17. (PMID:16054936)
- Blindness (HP:0000618): Blindness is the condition of lacking visual perception defined as a profound reduction in visual perception. On the 6m visual acuity scale, blindness is defined as less than 3/60. On the 20ft visual acuity scale, blindness is defined as less than 20/400. On the decimal visual acuity scale, blindness is defined as less than 0.05. Blindness is typically characterized by a visual field of no greater than 10 degrees in radius around central fixation. Evidence: IEA. (OMIM:609634)
- Photophobia (HP:0000613): Excessive sensitivity to light with the sensation of discomfort or pain in the eyes due to exposure to bright light. Evidence: PCS. Frequency: 16/18. (PMID:16054936)
- Phonophobia (HP:0002183): An abnormally heightened sensitivity to loud sounds. Evidence: PCS. Frequency: 16/17. (PMID:16054936)
- Hemiparesis (HP:0001269): Loss of strength in the arm, leg, and sometimes face on one side of the body. Hemiplegia refers to a complete loss of strength, whereas hemiparesis refers to an incomplete loss of strength. Evidence: IEA. (OMIM:609634)
- Autosomal dominant inheritance (HP:0000006): 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:16054936)
These phenotypes are associated with the disease migraine, familial hemiplegic, 3 (OMIM:609634).