(Marie Joubert, 20th century, Canadian neurologist), belongs to the group of cerebellar hypoplasias and is characterized by vermian hypoplasia or aplasia with cerebellar hemispheres that appear disconnected on MR. This is an autosomal recessive disorder found in children with breathing abnormalities (periodic hyperpnoea), developmental delay, ataxia and abnormal eye movements. MR may show other midline abnormalities such as corpus callosum agenesis or an ectopic posterior pituitary gland.