Phenotypes associated with the disease spinocerebellar ataxia 50 (OMIM:620158):
- Action tremor (HP:0002345): A tremor present when the limbs are active, either when outstretched in a certain position or throughout a voluntary movement. Evidence: PCS. Frequency: 1/17. (PMID:34788392)
- Middle age onset (HP:0003596): A type of adult onset with onset of symptoms at the age of 40 to 60 years. Evidence: PCS. Frequency: 15/17. (PMID:34788392)
- Diplopia (HP:0000651): Diplopia is a condition in which a single object is perceived as two images, it is also known as double vision. Evidence: PCS. Frequency: 3/16. (PMID:34788392)
- Hearing impairment (HP:0000365): A decreased magnitude of the sensory perception of sound. Evidence: PCS. Frequency: 3/17. (PMID:34788392)
- Memory impairment (HP:0002354): An impairment of memory as manifested by a reduced ability to remember things such as dates and names, and increased forgetfulness. Evidence: PCS. Frequency: 1/16. (PMID:34788392)
- 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: PCS. Frequency: 2/16. (PMID:34788392)
- 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: PCS. Frequency: 5/12. (PMID:34788392)
- Late onset (HP:0003584): A type of adult onset with onset of symptoms after the age of 60 years. Evidence: PCS. Frequency: 1/17. (PMID:34788392)
- Ataxia (HP:0001251): Ataxia refers to impaired coordination of voluntary muscle movement. Cerebellar ataxia refers to ataxia due to dysfunction of the cerebellum. This causes a variety of elementary neurological deficits including asynergy (lack of coordination between muscles, limbs and joints), dysmetria (lack of ability to judge distances that can lead to under- or overshoot in grasping movements), and dysdiadochokinesia (inability to perform rapid movements requiring antagonizing muscle groups to be switched on and off repeatedly). Evidence: PCS. Frequency: 17/17. (PMID:34788392)
- Postural tremor (HP:0002174): A type of tremors that is triggered by holding a limb in a fixed position. Evidence: PCS. Frequency: 1/17. (PMID:34788392)
- Chorea (HP:0002072): Chorea (Greek for 'dance') refers to widespread arrhythmic involuntary movements of a forcible, jerky and restless fashion. It is a random-appearing sequence of one or more discrete involuntary movements or movement fragments. Movements appear random because of variability in timing, duration or location. Each movement may have a distinct start and end. However, movements may be strung together and thus may appear to flow randomly from one muscle group to another. Chorea can involve the trunk, neck, face, tongue, and extremities. Evidence: PCS. Frequency: 1/17. (PMID:34788392)
- Impaired executive functioning (HP:0033051): A disturbance of executive functioning, which is broadly defined as the set of abilities that allow for the planning, executing, monitoring, and self-correcting of goal-directed behavior while inhibiting task-irrelevant behavior. At least some degree of executive skill is needed to complete most cognitive tasks, and deficits in executive abilities are central to many clinical conditions, including fronto-temporal dementia. Evidence: PCS. Frequency: 2/16. (PMID:34788392)
- Nystagmus (HP:0000639): Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms. Evidence: PCS. Frequency: 13/16. (PMID:34788392)
- Young adult onset (HP:0011462): Onset of disease at the age of between 16 and 40 years. Evidence: PCS. Frequency: 1/17. (PMID:34788392)
- Froment sign (HP:0032121): An abnormal result of a physical examination of the the hand that tests for palsy of the ulnar nerve. This nerve innervates the adductor pollicis and interossei muscles and thereby enables adduction of the thumb and extension of the interphalangeal joint. An abnormal result consists in reduced functionality and muscular weakness in the pinch grip between the thumb and index finger of the affected hand as the patient attempts to pinch a piece of paper that the examiner tries to pull away. The flexor pollicis longus muscle tries to compensate for the weakness by flexing the tip of the thumb at the interphalangeal joint. Evidence: PCS. Frequency: 1/17. (PMID:34788392)
- Ptosis (HP:0000508): The upper eyelid margin is positioned 3 mm or more lower than usual and covers the superior portion of the iris (objective); or, the upper lid margin obscures at least part of the pupil (subjective). Evidence: PCS. Frequency: 2/16. (PMID:34788392)
- 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:34788392)
- Head tremor (HP:0002346): An unintentional, oscillating to-and-fro muscle movement affecting head movement. Evidence: PCS. Frequency: 1/17. (PMID:34788392)
- Cerebellar vermis atrophy (HP:0006855): Wasting (atrophy) of the vermis of cerebellum. Evidence: PCS. Frequency: 3/12. (PMID:34788392)
- Myoclonus (HP:0001336): Very brief, involuntary random muscular contractions occurring at rest, in response to sensory stimuli, or accompanying voluntary movements. Evidence: PCS. Frequency: 4/17. (PMID:34788392)