Mutations of over 20 genes have been associated with ALS - the prominent ones being C9orf72, superoxide dismutase 1 (SOD1), fused in sarcoma (FUS), TAR DNA binding protein (TDP-43), OPTN, TBK1 and SQSTM1/p62, that accounts for 60% of familial and 11% of sporadic ALS cases. Here, SOD1 is linked to amyotrophic lateral sclerosis.