(de Morsier Syndrome)
Septo-optic dysplasia is a malformation of the front of the brain that occurs toward the end of the first month of gestation and includes optic nerve hypoplasia, absence of the septum pellucidum (the membranes that separate the front of the 2 lateral ventricles), and pituitary deficiencies.
Although the cause may be multiple, abnormalities of one particular gene (HESX1) have been found in some children with septo-optic dysplasia.
Symptoms may include decreased visual acuity in one or both eyes, nystagmus, strabismus, and endocrine dysfunction (including growth hormone deficiency, hypothyroidism, adrenal insufficiency, diabetes insipidus, and hypogonadism). Seizures may occur. Although some children have normal intelligence, many have learning disabilities, intellectual disability, cerebral palsy, or other developmental delay.