Association of prolactin receptor (PRLR) variants with prolactinomas by Gorvin, C, Newey, P, Rogers, A, Stokes, V, Neville, M, Lines, K, Ntali, G, Lees, P, Morrison, P, Singhellakis, P, Malandrinou, F, Karavitaki, N, Grossman, A, Karpe, F, Thakker, R