- Inability to walk (HP:0002540): Incapability to ambulate. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:391411)
- Slowed slurred speech (HP:0007164). Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:391411)
- 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: Frequent (HP:0040282). (ORPHA:391411)
- Seizure (HP:0001250): A seizure is an intermittent abnormality of nervous system physiology characterized by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:391411)
- Hyporeflexia (HP:0001265): Reduction of neurologic reflexes such as the knee-jerk reaction. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:391411)
- Weak voice (HP:0001621): Reduced intensity (volume) of speech. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:391411)
- 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: Frequent (HP:0040282). (ORPHA:391411)
- 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:391411)
- Akinesia (HP:0002304): Inability to initiate changes in activity or movement and to perform ordinary volitional movements rapidly and easily. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:391411)
- Scoliosis (HP:0002650): The presence of an abnormal lateral curvature of the spine. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:391411)
- Involuntary movements (HP:0004305): Involuntary contractions of muscle leading to involuntary movements of extremities, neck, trunk, or face. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:391411)
- Abnormal pyramidal sign (HP:0007256): Functional neurological abnormalities related to dysfunction of the pyramidal tract. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:391411)
- Short stepped shuffling gait (HP:0007311). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:391411)
- Leg muscle stiffness (HP:0008969). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:391411)
- Fatigue (HP:0012378): A subjective feeling of tiredness characterized by a lack of energy and motivation. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:391411)
- Brain atrophy (HP:0012444): Partial or complete wasting (loss) of brain tissue that was once present. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:391411)
- Abnormal nervous system physiology (HP:0012638): A functional anomaly of the nervous system. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:391411)
- Abnormality of movement (HP:0100022): An abnormality of movement with a neurological basis characterized by changes in coordination and speed of voluntary movements. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:391411)
- Myoclonus (HP:0001336): Very brief, involuntary random muscular contractions occurring at rest, in response to sensory stimuli, or accompanying voluntary movements. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:391411)
- 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:391411)
- Anarthria (HP:0002425): A defect in the motor ability that enables speech. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:391411)
- 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: Very frequent (HP:0040281). (ORPHA:391411)
- Dystonia (HP:0001332): An abnormally increased muscular tone that causes fixed abnormal postures. There is a slow, intermittent twisting motion that leads to exaggerated turning and posture of the extremities and trunk. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:391411)
- 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: Very frequent (HP:0040281). (ORPHA:391411)
- Bradykinesia (HP:0002067): Bradykinesia literally means slow movement, and is used clinically to denote a slowness in the execution of movement (in contrast to hypokinesia, which is used to refer to slowness in the initiation of movement). Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:391411)
- Postural instability (HP:0002172): A tendency to fall or the inability to keep oneself from falling; imbalance. The retropulsion test is widely regarded as the gold standard to evaluate postural instability, Use of the retropulsion test includes a rapid balance perturbation in the backward direction, and the number of balance correcting steps (or total absence thereof) is used to rate the degree of postural instability. Healthy subjects correct such perturbations with either one or two large steps, or without taking any steps, hinging rapidly at the hips while swinging the arms forward as a counterweight. In patients with balance impairment, balance correcting steps are often too small, forcing patients to take more than two steps. Taking three or more steps is generally considered to be abnormal, and taking more than five steps is regarded as being clearly abnormal. Markedly affected patients continue to step backward without ever regaining their balance and must be caught by the examiner (this would be called true retropulsion). Even more severely affected patients fail to correct entirely, and fall backward like a pushed toy soldier, without taking any corrective steps. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:391411)
- 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: Very frequent (HP:0040281). (ORPHA:391411)
These phenotypes are associated with the disease Atypical juvenile parkinsonism (ORPHA:391411).