This evidence was not unexpected with regard to the lower odds of association between the C9orf72 expansion and spinal onset and NIV, in consideration of the above discussed higher odds of association between the C9orf72 expansion and bulbar onset, among possible onsets, and given the higher association between the C9orf72 expansion and dementia, proven to induce less adherence and compliance to treatments, including NIV (Govaarts et al., 2016; Mandrioli et al., 2018b). Here, C9orf72 is linked to dementia.