Linkage of osteoporosis to chromosome 20p12 and association to BMP2 by Styrkarsdottir, U, Cazier, J, Kong, A, Rolfsson, O, Larsen, H, Bjarnadottir, E, Johannsdottir, V, Sigurdardottir, MS, Bagger, Y, Christiansen, C, Reynisdottir, I, Grant, S, Jonasson, K, Frigge, M, Gulcher, JR, Sigurdsson, G, Stefansson, K