C9orf72 expansions and neurodegenerative disease

Out of my league. I must admit that I know very little about the genetics of neurodegenerative disorders, but a recent article in the American Journal of Human Genetics caught my interest. Massive expansions of a hexanucleotide repeat in the first intron of C9orf72 are a known cause of frontotemporal lobar degeneration (FTLD)  and Amyotrophic Lateral Sclerosis (ALS). With a novel method for rapid screening for these expansions, the authors investigate a large cohort of patients with neurodegenerative disorders and population controls, providing an interesting example of how seemingly clear-cut monogenic disorders acquire an unanticipated degree of complexity. Continue reading