Genome-wide meta-analysis of myasthenia gravis uncovers new loci and provides insights into polygenic prediction by Braun, A, Shekhar, S, Levey, DF, Straub, P, Kraft, J, Panagiotaropoulou, GM, Heilbron, K, Awasthi, S, Meleka Hanna, R, Hoffmann, S, Stein, M, Lehnerer, S, Mergenthaler, P, Elnahas, AG, Topaloudi, A, Koromina, M, Palviainen, T, Asbjornsdottir, B, Stefansson, H, Skuladóttir, AT, Jónsdóttir, I, Stefansson, K, Reis, K, Esko, T