VCP and amyotrophic lateral sclerosis: A recent study of the existing ALS-causing genes has highlighted the role of structural variants in ALS pathogenesis and shown that genomic structural variants in valosin-containing protein (VCP), C9orf72, and Erb-B4 receptor tyrosine kinase 4 (ERBB4) genes impacted the risk of developing ALS, its progression and survival, the site of onset as well as the age of incidence [33].