- 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: 2/2. (PMID:22912398)
- Congenital onset (HP:0003577): A phenotypic abnormality that is present at birth. Evidence: PCS. Frequency: 1/2. (PMID:22912398)
- Difficulty standing (HP:0003698). Evidence: IEA. (OMIM:302500)
- Dysphagia (HP:0002015): Difficulty in swallowing. Evidence: PCS. Frequency: 1/2. (PMID:22912398)
- Juvenile onset (HP:0003621): Onset of signs or symptoms of disease between the age of 5 and 15 years. Evidence: IEA. (OMIM:302500)
- Strabismus (HP:0000486): A misalignment of the eyes so that the visual axes deviate from bifoveal fixation. The classification of strabismus may be based on a number of features including the relative position of the eyes, whether the deviation is latent or manifest, intermittent or constant, concomitant or otherwise and according to the age of onset and the relevance of any associated refractive error. Evidence: TAS. (OMIM:302500)
- 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: 2/2. (PMID:22912398)
- Dysarthria (HP:0001260): Dysarthric speech is a general description referring to a neurological speech disorder characterized by poor articulation. Depending on the involved neurological structures, dysarthria may be further classified as spastic, flaccid, ataxic, hyperkinetic and hypokinetic, or mixed. Evidence: PCS. Frequency: 1/2. (PMID:22912398)
- Hypotonia (HP:0001252): Hypotonia is an abnormally low muscle tone (the amount of tension or resistance to movement in a muscle). Even when relaxed, muscles have a continuous and passive partial contraction which provides some resistance to passive stretching. Hypotonia thus manifests as diminished resistance to passive stretching. Hypotonia is not the same as muscle weakness, although the two conditions can co-exist. Evidence: PCS. Frequency: 1/2. (PMID:22912398)
- Nonprogressive (HP:0003680): Applies to a disease manifestation that does not increase in scope or severity over the course of time, i.e., that does not worsen with age. Evidence: TAS. (OMIM:302500)
- 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: 2/2. (PMID:22912398)
- Infantile onset (HP:0003593): Onset of signs or symptoms of disease between 28 days to one year of life. Evidence: PCS. Frequency: 1/2. (PMID:22912398)
- Motor delay (HP:0001270): A type of Developmental delay characterized by a delay in acquiring motor skills. Evidence: PCS. Frequency: 2/2. (PMID:22912398)
- Abnormality of extrapyramidal motor function (HP:0002071): A neurological condition related to lesions of the basal ganglia leading to typical abnormalities including akinesia (inability to initiate changes in activity and perform volitional movements rapidly and easily), muscular rigidity (continuous contraction of muscles with constant resistance to passive movement), chorea (widespread arrhythmic movements of a forcible, rapid, jerky, and restless nature), athetosis (inability to sustain the muscles of the fingers, toes, or other group of muscles in a fixed position), and akathisia (inability to remain motionless). Evidence: PCS. Frequency: 0/2. (PMID:22912398)
- Intention tremor (HP:0002080): A type of kinetic tremor that occurs during target directed movement is called intention tremor. That is, an oscillatory cerebellar ataxia that tends to be absent when the limbs are inactive and during the first part of voluntary movement but worsening as the movement continues and greater precision is required (e.g., in touching a target such as the patient's nose or a physician's finger). Evidence: PCS. Frequency: 2/2. (PMID:22912398)
- Nystagmus (HP:0000639): Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms. Evidence: IEA. (OMIM:302500)
- X-linked recessive inheritance (HP:0001419): A mode of inheritance that is observed for recessive traits related to a gene encoded on the X chromosome. In the context of medical genetics, X-linked recessive disorders manifest in males (who have one copy of the X chromosome and are thus hemizygotes), but generally not in female heterozygotes who have one mutant and one normal allele. Evidence: PCS. (PMID:22912398)
- Slow saccadic eye movements (HP:0000514): An abnormally slow velocity of the saccadic eye movements. Evidence: PCS. Frequency: 1/2. (PMID:22912398)
- Neonatal hypotonia (HP:0001319): Muscular hypotonia (abnormally low muscle tone) manifesting in the neonatal period. Evidence: TAS. (OMIM:302500)
- Unsteady gait (HP:0002317). Evidence: PCS. Frequency: 2/2. (PMID:22912398)
These phenotypes are associated with the disease X-linked progressive cerebellar ataxia (OMIM:302500).