OPTN and amyotrophic lateral sclerosis: Apart from these genes, other less common genetic mutations have also been reported to be associated with ALS, such as mutations in OPTN (Optineurin), VABP (VAMP-associated protein B), UBQLN2 (Ubiquilin-2), VCP (Valosin containing protein), MATR3 (Matrin 3), TBK1 (TANK-binding kinase-1), NEK1 (NIMA-related kinase-1), and C21orf2 [45].