| A rare hereditary ataxia with characteristics of progressive cerebellar ataxia associated with disruption of visual fixation by saccadic intrusions. It presents with progressive gait, trunk and limb ataxia with pyramidal tract signs (increased tendon reflexes and Babinski sign), myoclonic jerks, fasciculations, cerebellar dysarthria, sensorimotor axonal neuropathy with impaired joint position, vibration, temperature, pain sensations, pes cavus, and saccadic intrusions with characteristic overshooting horizontal saccades, macrosaccadic oscillations, and increased velocity of larger saccades, without other eye movement disturbances. |