The analyzed cohort consisted of n = 17 C9orf72 mutation carriers covering the complete clinical spectrum from pure ALS, mixed ALS/FTD and pure FTD and n = 26 neurologic disease controls (ALS, ALS/FTD and FTD cases without C9orf72 mutation) with detailed information on each case given in Additional file 1: Table S1. This evidence concerns the gene C9orf72 and nervous system disorder.