VCP and amyotrophic lateral sclerosis: In addition to these three degenerative conditions, amyotrophic lateral sclerosis (ALS) and Parkinson's disease are linked to VCP mutations (Johnson et al., 2010; Spina et al., 2013; Benatar et al., 2013; Regensburger et al., 2017; Al-Obeidi et al., 2018).