Amyotrophic Lateral Sclerosis Causes

We do not know exactly what causes ALS. Although about 10% of cases of ALS are hereditary (run in families), the other 90% are not. A mutation of a gene called SOD1 has been identified in some of the hereditary cases, but we do not know what role the mutation plays in the disease.

Using an evidence-based approach, smoking was found to be more likely than not a risk factor for ALS based on two excellent studies by Kamel et al. and Nelson et al. Smoking has a broad public health impact, no redeeming features, and is a modifiable risk factor. Evidence also supported the conclusion that the following were probably not risk factors for ALS: trauma, physical activity, residence in rural areas, and alcohol consumption.