- Abnormality of eye movement (HP:0000496): An abnormality in voluntary or involuntary eye movements or their control. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:247234)
- 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:247234)
- 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: Very frequent (HP:0040281). (ORPHA:247234)
- 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: TAS. Frequency: Frequent (HP:0040282). (ORPHA:247234)
- Macular degeneration (HP:0000608): A nonspecific term denoting degeneration of the retinal pigment epithelium and/or retinal photoreceptor cells of the macula lutea. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:247234)
- Gaze-evoked nystagmus (HP:0000640): Nystagmus made apparent by looking to the right or to the left. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:247234)
- 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: TAS. Frequency: Frequent (HP:0040282). (ORPHA:247234)
- Abnormal vestibulo-ocular reflex (HP:0007670): An abnormality of the vestibulo-ocular reflex (VOR). The VOR attempts to keep the image stable on the retina. Ideally passive or active head movements in one direction are compensated for by eye movements of equal magnitude. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:247234)
- Impaired smooth pursuit (HP:0007772): An impairment of the ability to track objects with the ocular smooth pursuit system, a class of rather slow eye movements that minimizes retinal target motion. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:247234)
- Cerebellar cortical atrophy (HP:0008278): Atrophy (wasting) of the cerebellar cortex. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:247234)
- Abnormal autonomic nervous system physiology (HP:0012332): A functional abnormality of the autonomic nervous system. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:247234)
- Hypomimic face (HP:0000338): A reduced degree of motion of the muscles beneath the skin of the face, often associated with reduced facial crease formation. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:247234)
- Sensory neuropathy (HP:0000763): Peripheral neuropathy affecting the sensory nerves. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:247234)
- Spasticity (HP:0001257): A motor disorder characterized by a velocity-dependent increase in tonic stretch reflexes with increased muscle tone, exaggerated (hyperexcitable) tendon reflexes. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:247234)
- 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: TAS. Frequency: Occasional (HP:0040283). (ORPHA:247234)
- Abnormal cranial nerve morphology (HP:0001291): Structural abnormality affecting one or more of the cranial nerves, which emerge directly from the brain stem. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:247234)
- Parkinsonism (HP:0001300): Characteristic neurologic anomaly resulting from degeneration of dopamine-generating cells in the substantia nigra, a region of the midbrain, characterized clinically by shaking, rigidity, slowness of movement and difficulty with walking and gait. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:247234)
- Hyperreflexia (HP:0001347): Hyperreflexia is the presence of hyperactive stretch reflexes of the muscles. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:247234)
- Dysphagia (HP:0002015): Difficulty in swallowing. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:247234)
- Rigidity (HP:0002063): Continuous involuntary sustained muscle contraction. When an affected muscle is passively stretched, the degree of resistance remains constant regardless of the rate at which the muscle is stretched. This feature helps to distinguish rigidity from muscle spasticity. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:247234)
- Dysdiadochokinesis (HP:0002075): A type of ataxia characterized by the impairment of the ability to perform rapidly alternating movements, such as pronating and supinating his or her hand on the dorsum of the other hand as rapidly as possible. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:247234)
- Akinesia (HP:0002304): Inability to initiate changes in activity or movement and to perform ordinary volitional movements rapidly and easily. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:247234)
- Resting tremor (HP:0002322): A resting tremor occurs when muscles are at rest and becomes less noticeable or disappears when the affected muscles are moved. Resting tremors are often slow and coarse. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:247234)
- Shuffling gait (HP:0002362): A type of gait (walking) characterized by by dragging one's feet along or without lifting the feet fully from the ground. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:247234)
- Babinski sign (HP:0003487): Upturning of the big toe (and sometimes fanning of the other toes) in response to stimulation of the sole of the foot. If the Babinski sign is present it can indicate damage to the corticospinal tract. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:247234)
- Urinary incontinence (HP:0000020): Loss of the ability to control the urinary bladder leading to involuntary urination. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:247234)
- 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: TAS. Frequency: Very rare (HP:0040284). (ORPHA:247234)
- 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: TAS. Frequency: Very rare (HP:0040284). (ORPHA:247234)
These phenotypes are associated with the disease Sporadic adult-onset ataxia of unknown etiology (ORPHA:247234).