SARM1 and amyotrophic lateral sclerosis: Given that the I114T SOD1 allele shows incomplete penetrance (Lopate et al., 2010) and the L17P FIG4 allele has previously only been associated with CMT4J in combination with a null allele (Nicholson et al., 2011), it raises the possibility that an interaction with the SARM1 GoF alleles is critical for pathogenesis in these ALS cases.