A common variant in the 3'UTR of the GRIK4 glutamate receptor gene affects transcript abundance and protects against bipolar disorder. by Pickard, B, Knight, H, Hamilton, R, Soares, D, Walker, R, Boyd, J, Machell, J, Maclean, A, McGhee, K, Condie, A, Porteous, D, St Clair, D, Davis, I, Blackwood, D, Muir, W