Future studies could also clarify the association between DNAm-age acceleration and other ALS phenotypes (e.g., severity), or in ALS patients with other mutations (e.g., in SOD1), and different neurodegenerative phenotypes in the longitudinal Genetic Frontotemporal dementia Initiative cohort [6] and the Dominantly inherited Alzheimer’s disease cohort [8] (Supplementary discussion). The gene discussed is SOD1; the disease is amyotrophic lateral sclerosis.