Disruption of Nucleolar Integrity and Dysregulation of RNA Splicing in C9orf72-FTD/ALS Background and Research Motivation The hexanucleotide repeat expansion (GGGGCC)n in the C9orf72 gene is the most common genetic cause of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). Studies have shown that these repeat sequences not only...