E478G and Q398X are ALS-linked optineurin mutants (Maruyama et al., 2010): E478G is a missense mutation localized in the ubiquitin binding domain (UBD), while Q398X is a truncation mutation due to an immature stop codon, where the entire UBD is deleted (Maruyama et al., 2010). The gene discussed is OPTN; the disease is amyotrophic lateral sclerosis.