Help docs! i'm trying to find out what causes motor neurone disease?

Lou gehrig's disease: Motor neuron disease is a group of disorders that destroy the motor neurons or the nerves responsible for movement. The disease is progressive without known cure. They can be hereditary or arise sporadically. The causes are unknown.

Would like to know: The cause of sporadic ALS is unknown, but we do know that 10% of cases are familial, and 25% of these exhibit mutations in the gene encoding copper/zinc superoxide dismutase.