Importantly, ALS is in a large proportion of cases a form fruste of the frontotemporal dementia-ALS complex, which may be associated with mutations in either the C9orf72 gene, the latter as a GGGGCC hexanucleotide repeat expansion, or in its target the TDP43 gene (DeJesus-Hernandez et al., 2011; Renton et al., 2011). Glial pathology may prove to be contributory in FTD-ALS just as in the SOD1 mutant ALS models thus far examined, and if so, FTD-ALS, like sporadic ALS, may similarly prove an amenable and appropriate target for glial cell-based therapeutics (Serio et al., 2013).
