Intermediate HTT CAG repeats worsen disease severity in amyotrophic lateral sclerosis.

Competing Interests: Competing interests: AChio serves on scientific advisory boards for Mitsubishi Tanabe, Roche, Biogen, Denali Pharma, AC Immune, Biogen, Lilly, and Cytokinetics and has received a research grant from Biogen. BT holds the US, Canadian and European patents on the clinical testing and therapeutic intervention for the hexanucleotide repeat expansion in C9orf72. BT and SS received research support from Cerevel Therapeutics. ACalvo has received a research grant from Cytokinetics. MG has received grants from the American Academy of Neurology, the American Brain Foundation and the ALS Association.