C9orf72 and early-onset autosomal dominant Alzheimer disease: To determine whether expanded GGGGCC repeat sense foci are a characteristic and specific feature of C9FTLD, we performed RNA FISH on 8 C9FTLD cases, 7 FTLD-TDP cases without C9orf72 mutation, 3 Alzheimer’s disease cases and 10 age-matched controls (Table 1).