C9orf72 and normal pressure hydrocephalus: The mean age at sample collection was 44.0 years (s.d. 13.6, range 21.9–65.4) for healthy controls, 38.1 years (s.d. 10.4, range 17–59) for migraine controls, 71.2 years for NPH controls (s.d. 7.5, range 58–85), 43.0 years for presymptomatic C9orf72 mutation carriers (s.d. 9.7, range 23.1–64.2), 57.6 years for symptomatic C9orf72 mutation carriers (s.d. 9.0, range 35.7–75.4) and 59.0 years for sporadic ALS (s.d. 11.3, range 37.8–80.0) (Extended Data Table 1).