Brain magnetic resonance imaging results for 12 of 21 probands with mutations, showing the typical midbrain-hindbrain malformation known as the MTS. All panels display axial sections at the pontine or pontomesencephalic junction showing the MTS. A–L, respectively, patients MTI012, MTI286, COR002a, COR083, COR145, COR109, COR084, COR125, MTI333b, MTI154, MTI125, and MTI487.