Amyotrophic Lateral Sclerosis Risk Factors
ALS risk is increased by selected genetic factors and by several non-genetic exposures reported in observational studies and meta-analyses. Monogenic mutations in more than 30 genes are associated with approximately 10% of ALS cases. [1]
Genetic Predisposition
- Familial ALS with inherited monogenic mutations is associated with a minority of ALS cases (about 10%). [1]
Age and Sex
- Increasing age is associated with ALS risk, based on epidemiologic patterns reported in systematic reviews. [1]
Head and Physical Trauma
- Prior trauma is associated with higher ALS risk (pooled OR 1.51, 95% CI 1.32 to 1.73). [2]
- Associations are reported for trunk trauma, head trauma, and lower-limb trauma. [2]
- Trauma within 5 years is associated with increased ALS diagnosis risk (pooled OR 1.84, 95% CI 1.56 to 2.17). [2]
Military Service
- Military service is associated with increased ALS risk (pooled OR 1.34, 95% CI 1.11 to 1.61). [3]
Pesticide and Lead Exposure
- Pesticide exposure is associated with increased ALS risk (pooled OR 1.96, 95% CI 1.70 to 2.26). [3]
- Lead exposure is associated with increased ALS risk (pooled OR 2.31, 95% CI 1.44 to 3.71). [3]
- Chronic occupational lead exposure is also reported as associated with higher ALS risk in a meta-umbrella review. [4]
Electric Shock
- Electric shock is associated with increased ALS risk (pooled OR 2.72, 95% CI 1.62 to 4.56). [3]
Physical Activity
- Physical activity is reported as associated with increased ALS risk (pooled OR 1.06, 95% CI 1.04 to 1.09). [3]
Smoking
- Smoking is reported as a weak risk factor for ALS in women in a systematic review and meta-analysis of observational studies. [1]