In 1993, MDA investigators found a gene on chromosome 21 that, when flawed, can lead to ALS.The gene is for an enzyme called SOD1, or superoxide dismutase 1.Although a very small percentage of people with ALS have this gene flaw, researchers believe research into how the mutated gene causes ALS may carry over to the non-genetic form as well. Studies suggest that the SOD1 enzyme normally protects motor neurons against a type of damage called oxidative stress .It's now thought that oxidative stress plays an important role in ALS, at least in its early stages.
Neurotransmitters carry messagesfrom one nerve cell to another.
Excitatory neurotransmitters cause the nerve cell that receives the message to send a message that stimulates, or excites, another nerve cell. In some people with ALS, there may be too much glutamate in the fluid surrounding nerve cells. Some researchers believe that ALS is caused by a faulty immune system. In ALS, they theorize, the immune system may mistakenly destroy motor neurons.