Candidate glutamatergic and dopaminergic pathway gene variants do not influence Huntington's disease motor onset.

"Conflict of interest The authors declare that they have no conflict of interest."

"The authors thank Drs. Ignacio Muñoz-Sanjuan, Seung Kwak, and Jamshid Arjomand from CHDI Foundation, Inc., as well as the HD families, whose participation in genetic studies made this work possible; the COHORT co-investigators and contributors (see “Appendix”); contributors to the HD-MAPS study, Drs. Alexandra Durr, Adam Rosenblatt, Luigi Frati, Susan Perlman, P. Michael Conneally, Mary Lou Klimek, Melissa Diggin, Tiffany Hadzi, and Ayana Duckett; the Harvard Brain Tissue Resource Center at McLean Hospital; and the National Neurological Research Specimen Bank at the VA West Los Angeles Healthcare Center. EMR is the recipient of a scholarship from the Fundação para a Ciência e a Tecnologia of Portugal (SFRH/BD/44335/2008). Study funding was supported by NIH grants from the NINDS NS16367 (The Massachusetts HD Center Without Walls) and NS32765, and the CHDI Foundation, Inc."