Contributor: Gordon K. Klintworth
De Morsier syndrome (septooptic dysplasia, OMIM # 182230) is an inherited syndrome characterized by optic nerve hypoplasia, agenesis of the septum pellucidum and abnormalities of the pituitary gland. Pituitary insufficiency is reflected in deficient secretions of growth hormone, ACTH, luteinizing hormone, follicle-stimulating hormone and this leads to pituitary dwalfism and panhypopituitarism. Other midline central nervous system abnormalities may be present in the corpus callosum and cerebellum. Posterior fossa abnormalities may resemble those in Dandy-Walker syndrome. A see-saw nystagmus may be associated. The condition is probably caused by a mutation in the HESXI gene.