Duplication of the Williams–Beuren critical region: case report and further delineation of the phenotypic spectrum. Issue 3 (29th February 2008) - Orellana, C; Bernabeu, J; Monfort, S; Roselló, M; Oltra, S; Ferrer, I; Quiroga, R; Martínez-Garay, I; Martínez, F