ALS Home > Causes of ALS
At this time, it is not known why ALS (amyotrophic lateral sclerosis) occurs. It's also unknown why the disease occurs in some people and not others. ALS research scientists are still examining a number of possible causes associated with ALS, including genetic mutations, glutamate, autoimmune responses, and the environment. Future research may show that there are many possible ALS causes.
The cause or causes of ALS (amyotrophic lateral sclerosis) are not known, and scientists do not yet know why ALS strikes some people and not others.
ALS research scientists are looking at a number of possible ALS causes, including:
- Autoimmune responses
An important step toward finding the causes of ALS came in 1993, when research scientists discovered that mutations in the gene that produces the superoxide dismutase 1 (SOD1) enzyme were associated with some cases of familial ALS.
(Click Familial Amyotrophic Lateral Sclerosis for more information about familial ALS.)
The SOD1 enzyme is a powerful antioxidant that protects the body from damage caused by free radicals. Free radicals are highly reactive molecules that are produced by cells during normal metabolism. If these free radicals are not neutralized, they can accumulate and cause random damage to the DNA and proteins within cells.
Although it is not yet clear how the SOD1 gene mutation leads to motor neuron degeneration, researchers have theorized that an accumulation of free radicals may result from the faulty functioning of this gene. In support of this theory, animal studies have shown that motor neuron degeneration and deficits in motor function accompany the presence of the SOD1 mutation.