VCP and amyotrophic lateral sclerosis: VCP mutations are also associated with 1–2% of cases of amyotrophic lateral sclerosis (ALS), familial hereditary spastic paraplegia (HSP) and Charcot-Marie-Tooth 2 (CMT2) disease (Abramzon et al., 2012; de Bot et al., 2012; Gonzalez et al., 2014).