Pontine tegmental cap dysplasia is a rare neurologic condition first described by Barth et al. in 2007. It is characterized by a vaulted pontine tegmentum projecting into the fourth ventricle and ventral pontine hypoplasia. Patients present with developmental delay, cerebellar and pyramidal abnormalities, cranial nerve dysfunction, and various extracranial malformations. The condition is thought to occur as a result of aberrant neuronal axonal guidance during embryologic development. Its genetic etiology has not been identified. We describe a further case of this rare condition with several features not previously reported, including aortic arch hypoplasia and mirror movements.