- 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:88644)
- 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: Very frequent (HP:0040281). (ORPHA:88644)
- Gait disturbance (HP:0001288): The term gait disturbance can refer to any disruption of the ability to walk. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:88644)
- Upper motor neuron dysfunction (HP:0002493): A functional anomaly of the upper motor neuron. The upper motor neurons are neurons of the primary motor cortex which project to the brainstem and spinal chord via the corticonuclear, corticobulbar and corticospinal (pyramidal) tracts. They are involved in control of voluntary movements. Dysfunction leads to weakness, impairment of fine motor movements, spasticity, hyperreflexia and abnormal pyramidal signs. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:88644)
- Short attention span (HP:0000736): Reduced attention span characterized by distractibility and impulsivity. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:88644)
- 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: Frequent (HP:0040282). (ORPHA:88644)
- Motor delay (HP:0001270): A type of Developmental delay characterized by a delay in acquiring motor skills. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:88644)
- Diminished deep tendon reflex (HP:0001315): A reduction (hyporeflexia) or complete absence (areflexia) of the involuntary muscle contraction normally elicited by a reflex stimulus, such as tapping a deep tendon. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:88644)
- Hyperreflexia (HP:0001347): Hyperreflexia is the presence of hyperactive stretch reflexes of the muscles. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:88644)
- Lower limb spasticity (HP:0002061): Spasticity (velocity-dependent increase in tonic stretch reflexes with increased muscle tone and hyperexcitable tendon reflexes) in the muscles of the lower limbs, hips, and pelvis. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:88644)
- Fasciculations (HP:0002380): Fasciculations are observed as small, local, involuntary muscle contractions (twitching) visible under the skin. Fasciculations result from increased irritability of an axon (which in turn is often a manifestation of disease of a motor neuron). This leads to sporadic discharges of all the muscle fibers controlled by the axon in isolation from other motor units. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:88644)
- Skeletal muscle atrophy (HP:0003202): The presence of skeletal muscular atrophy (which is also known as amyotrophy). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:88644)
- 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: Frequent (HP:0040282). (ORPHA:88644)
- Lower limb muscle weakness (HP:0007340): Weakness of the muscles of the legs. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:88644)
- Urinary incontinence (HP:0000020): Loss of the ability to control the urinary bladder leading to involuntary urination. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:88644)
- 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. Frequency: Occasional (HP:0040283). (ORPHA:88644)
- 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: TAS. Frequency: Occasional (HP:0040283). (ORPHA:88644)
- Abnormal saccadic eye movements (HP:0000570): An abnormality of eye movement characterized by impairment of fast (saccadic) eye movements. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:88644)
- Ophthalmoparesis (HP:0000597): Ophthalmoplegia is a paralysis or weakness of one or more of the muscles that control eye movement. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:88644)
- Intellectual disability (HP:0001249): The term intellectual disability or intellectual developmental disorder is used to describe significantly sub-average intellectual and adaptive functioning based on clinical assessment and as measured by individually administered, appropriately normed, standardized and validated tests of intellectual functioning and adaptive behavior, with onset during the developmental period from infancy through adolescence. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:88644)
- 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:88644)
- Dysmetria (HP:0001310): A type of ataxia characterized by the inability to carry out movements with the correct range and motion across the plane of more than one joint related to incorrect estimation of the distances required for targeted movements. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:88644)
- Neonatal hypotonia (HP:0001319): Muscular hypotonia (abnormally low muscle tone) manifesting in the neonatal period. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:88644)
- Decreased fetal movement (HP:0001558): An abnormal reduction in quantity or strength of fetal movements. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:88644)
- Pes cavus (HP:0001761): An increase in height of the medial longitudinal arch of the foot that does not flatten on weight bearing (i.e., a distinctly hollow form of the sole of the foot when it is bearing weight). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:88644)
- Clumsiness (HP:0002312): Lack of physical coordination resulting in an abnormal tendency to drop items or bump into objects. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:88644)
- Abnormal cerebral white matter morphology (HP:0002500): An abnormality of the cerebral white matter. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:88644)
- Scoliosis (HP:0002650): The presence of an abnormal lateral curvature of the spine. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:88644)
- Kyphosis (HP:0002808): Exaggerated anterior convexity of the thoracic vertebral column. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:88644)
- EMG: neuropathic changes (HP:0003445): The presence of characteristic findings of denervation on electromyography (fibrillations, positive sharp waves, and giant motor unit potentials). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:88644)
- Chronic axonal neuropathy (HP:0007267): An abnormality characterized by chronic impairment of the normal functioning of the axons. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:88644)
- 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: Occasional (HP:0040283). (ORPHA:88644)
- Ankle clonus (HP:0011448): Clonus is an involuntary tendon reflex that causes repeated flexion and extension of the foot. Ankle clonus is tested by rapidly flexing the foot upward. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:88644)
- Square-wave jerks (HP:0025402): Square wave jerks are saccadic eye movements which, when recorded with open eyes are considered to be a pathological sign, caused by fixation instability, and pointing to a central neurological lesion. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:88644)
- Arm dystonia (HP:0031960): A type of dystonia (abnormally increased muscular tone causing fixed abnormal postures) that affects muscles of the arms. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:88644)
- Polyneuropathy (HP:0001271): A generalized disorder of peripheral nerves. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:88644)
- Abnormality of the respiratory system (HP:0002086): An abnormality of the respiratory system, which include the airways, lungs, and the respiratory muscles. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:88644)
- Impaired vibratory sensation (HP:0002495): A decrease in the ability to perceive vibration. Clinically, this is usually tested with a tuning fork which vibrates at 128 Hz and is applied to bony prominences such as the malleoli at the ankles or the metacarpal-phalangeal joints. There is a slow decay of vibration from the tuning fork. The degree of vibratory sense loss can be crudely estimated by counting the number of seconds that the examiner can perceive the vibration longer than the patient. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:88644)
- Sensory axonal neuropathy (HP:0003390): An axonal neuropathy of peripheral sensory nerves. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:88644)
- Motor polyneuropathy (HP:0007178). Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:88644)
- Atrophy/Degeneration affecting the brainstem (HP:0007366). Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:88644)
These phenotypes are associated with the disease Autosomal recessive ataxia, Beauce type (ORPHA:88644).