Causes
By Mayo Clinic staffIn ALS, the nerve cells that control the movement of your muscles gradually die, so your muscles progressively weaken and begin to waste away. Up to 1 in 10 cases of ALS is inherited. But the remainder appear to occur randomly.
Researchers are studying several possible causes of ALS, including:
- Gene mutation. Various genetic mutations can lead to inherited forms of ALS, which appear nearly identical to the non-inherited forms.
- Chemical imbalance. People who have ALS typically have higher than normal levels of glutamate, a chemical messenger in the brain, around the nerve cells in their spinal fluid. Too much glutamate is known to be toxic to some nerve cells.
- Disorganized immune response. Sometimes a person's immune system begins attacking some of his or her body's own normal cells, and scientists have speculated that this may trigger the process that results in ALS.
- Protein mishandling. There's evidence that mishandled proteins within the nerve cells can lead to a gradual accumulation of abnormal forms of these proteins in the cells, eventually causing the nerve cells to die.
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