Figure 1.

Schematic depiction of risk factors in ALS. ALS risk factors can be divided into two main categories: genetic and environmental. Well-documented genetic factors include mutations in superoxide dismutase 1 (SOD1 gene), mutation in TAR DNA binding protein (TARDBP), a hexanucleotide repeat expansion (GGGGCC) in the first intron of the C9orf72 gene, and mutations in TANK-binding kinase 1 (TBK1). The researched environmental risk factors are BMI and nutritional state and exposure to heavy metals, pesticides, and electromagnetic fields.