OPTN and amyotrophic lateral sclerosis: For what concerns ALS, more than 40 OPTN variants have been reported both in sALS and in fALS, with a limited number of mutations being shared between populations of different ethnicity (Maruyama et al. 2010; Del Bo et al. 2011; Tümer et al. 2012; van Blitterswijk et al. 2012b; Iida et al. 2012; Beeldman et al. 2015; Gotkine et al. 2021).