Previous studies had established a strong link between ALS and mutations and polymorphisms of OPTN (7), with three types of mutations in OPTN (a homozygous deletion of exon 5, a homozygous Q398X nonsense mutation, and a heterozygous E478G missense mutation) identified in Japanese ALS patients (8, 9). This evidence concerns the gene OPTN and amyotrophic lateral sclerosis.