Motor neurone disease (amyotrophic lateral sclerosis) is a relatively rare progressive, degenerative neurological disease with a prevalence of about 7 per 100,000 population. The cause is usually unknown, although in about 5% there is a family history and of these in 20% (that is, 1% of the total MND/ALS population) an abnormal gene can be found - the superoxide dismutase 1 gene on chromosome 21. There is no curative treatment but the glutamate blocker, riluzole, has been shown in trials to reduce the rate of progression and may extend life by a few months. The prognosis is in the order of three to five years.