Phenotypes associated with the disease Spinocerebellar ataxia type 15/16 (ORPHA:98769):
- 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: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:98769)
- 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: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98769)
- Hyperreflexia (HP:0001347): Hyperreflexia is the presence of hyperactive stretch reflexes of the muscles. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98769)
- Gait ataxia (HP:0002066): A type of ataxia characterized by the impairment of the ability to coordinate the movements required for normal walking. Gait ataxia is characteirzed by a wide-based staggering gait with a tendency to fall. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98769)
- 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: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98769)
- Head tremor (HP:0002346): An unintentional, oscillating to-and-fro muscle movement affecting head movement. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98769)
- Upper limb postural tremor (HP:0007351): A type of tremors that is triggered by holding an arm in a fixed position. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98769)
- Tremor by anatomical site (HP:0030188): Tremor classified by the affected body part. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:98769)