| Main clinical features
|
associate lower-motor-neuron disease with progressive myoclonic epilepsy in childhood
onset of motor deficits at the age of 3 years after normal developmental milestones. and progressive muscle paralysis is caused by the involvement of lower motor neurons
disorder is progressive, and usually results in loss of ambulation and early death from respiratory insufficiency
milder reduction of enzymatic activity leads to a later-onset of symptoms restricted to spinal-cord motor neurons and other areas of the CNS |