MRI studies comparing normal subjects (A–C) with patients with HGPPS (D–F) at similar anatomical levels. CC – corpus callosum, P - pons, M - medulla, * - fourth ventricle. Reproduced with permission from Jen JC, Chan WM, Bosley TM, et al., “Mutations in a human ROBO gene disrupt hindbrain axon pathway crossing and morphogenesis,” Science. Jun 4 2004;304(5676):1509–1513. 368×235mm (72×72 DPI).