C9orf72 and frontotemporal dementia: The 25 publications with the strongest citation burst are listed in Fig. 6B. The highest and second highest citation burst references were generated by DeJesus-Hernandez et al. and Renton et al. These authors identified a non-coding expanded GGGGCC hexanucleotide repeat in C9orf72 as the cause of chromosome 9p-linked ALS/FTD and showed that this genetic defect is the most common cause of ALS and FTD [14,15].