C9orf72 and dementia: Overall, the combined cumulative incidence of ALS and any-cause dementia by age 80 was 66% (57%–73%) in C9orf72 HRE carriers compared to 5.8% (4.5%–7.0%) in controls, assuming survival to this age, or 58% (50%–64%) in carriers compared to 5.1% (4.1%–6.4%) in controls accounting for other cause mortality.