Large-scale meta-analysis of genome-wide association data identifies six new risk loci for Parkinson's disease by Nalls, M, Pankratz, N, Lill, C, Do, C, Hernandez, D, Saad, M, DeStefano, A, Kara, E, Bras, J, Sharma, M, Schulte, C, Keller, M, Arepalli, S, Letson, C, Edsall, C, Stefansson, H, Liu, X, Pliner, H, Lee, J, Cheng, R, Ikram, M, Ioannidis, J, Hadjigeorgiou, G, Bis, J, Martinez, M, Perlmutter, J, Goate, A, Marder, K, Fiske, B, Sutherland, M, Xiromerisiou, G, Myers, R, Clark, L, Stefansson, K, Hardy, J, Heutink, P, Chen, H, Wood, N, Houlden, H, Payami, H, Brice, A, Scott, W, Gasser, T, Bertram, L, Eriksson, N, Foroud, T, Singleton, A