- 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:363654)
- Cogwheel rigidity (HP:0002396): A type of rigidity in which a muscle responds with cogwheellike jerks to the use of constant force in bending the limb (i.e., it gives way in little, repeated jerks when the muscle is passively stretched). Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:363654)
- 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:363654)
- 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: Frequent (HP:0040282). (ORPHA:363654)
- 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:363654)
- Hyperactive deep tendon reflexes (HP:0006801). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:363654)
- Mask-like facies (HP:0000298): A lack of facial expression often with staring eyes and a slightly open mouth. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:363654)
- 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: Occasional (HP:0040283). (ORPHA:363654)
- Spastic paraparesis (HP:0002313): Partial loss of the ability to move the lower limbs accompanied by spasticity of the lower limbs. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:363654)
- Diffuse cerebral atrophy (HP:0002506): Diffuse unlocalised atrophy affecting the cerebrum. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:363654)
- Lateral ventricle dilatation (HP:0006956). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:363654)
- Dilated third ventricle (HP:0007082): An increase in size of the third ventricle. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:363654)
- 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:363654)
- Scissor gait (HP:0012407): A type of spastic paraparetic gait in which the muscle tone in the adductors is marked. It is characterized by hypertonia and flexion in the legs, hips and pelvis accompanied by extreme adduction leading to the knees and thighs hitting, or sometimes even crossing, in a scissors-like movement. The opposing muscles (abductors) become comparatively weak from lack of use. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:363654)
These phenotypes are associated with the disease X-linked parkinsonism-spasticity syndrome (ORPHA:363654).