PDE4D and ischemic stroke: In a previous study, Gretarsdottir et al. (2003[8]) performed a genome-wide association study in an Iceland population (864 patients with ischemic stroke and 908 controls), finding a strong association with some PDE4D gene polymorphisms (rs966221, rs12153798, rs12188950, rs702553, rs2910829, and rs1396476), and microsatellite markers.