Most ALS cases occur without a clearly identified cause and are therefore referred to as sporadic ALS (SALS). In contrast, a positive family history is present in ∼10% of all patients (familial ALS; FALS) (van Blitterswijk et al., 2012; Nguyen et al., 2018) and these genetic mutations cause ALS in a mostly autosomal-dominant manner (Supplementary Table 1 and Figure 2). However, several recently discovered mutations have been described in patients diagnosed with SALS (Renton et al., 2014; Al Sultan et al., 2016; Taylor et al., 2016). The patterns of selective MN degeneration and vulnerability are similar between FALS and SALS (Comley et al., 2015), implying that shared molecular mechanisms exist between the two conditions.