Merck Manual

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Septo-Optic Dysplasia

(de Morsier Syndrome)


Stephen J. Falchek

, MD, Nemours/Alfred I. duPont Hospital for Children

Medically Reviewed Dec 2018 | Modified Sep 2022
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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 membrane that separates 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 of septo-optic dysplasia 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.

Diagnosis of Septo-Optic Dysplasia

  • MRI

Diagnosis of septo-optic dysplasia is by MRI. All children diagnosed with this anomaly should be screened for pituitary endocrine abnormalities and developmental dysfunction.

The increasing use of fetal ultrasonography, which can detect absence of the septum pellucidum and increased ventricular size, followed by fetal MRI, add to the early detection of this malformation.

Treatment of Septo-Optic Dysplasia

  • Supportive care

  • Pituitary hormone replacement

Treatment of septo-optic dysplasia is supportive, including replacement of any deficient pituitary hormones.

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NOTE: This is the Professional Version. CONSUMERS: View Consumer Version
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