Septo-optic dysplasia spectrum

In most cases of septo-optic dysplasia, the cause of the disorder is unknown. Researchers suspect that a combination of genetic and environmental factors may play a role in causing this disorder. Proposed environmental risk factors include viral infections, specific medications, and a disruption in blood flow to certain areas of the brain during critical periods of development.

At least three genes have been associated with septo-optic dysplasia, although mutations in these genes appear to be rare causes of this disorder. The three genes, HESX1, OTX2, and SOX2, all play important roles in early development. In particular, they are essential for the formation of the eyes, the pituitary gland, and structures at the front of the brain (the forebrain) such as the optic nerves. Mutations in any of these genes disrupt the early development of these structures, which leads to the major features of septo-optic dysplasia.

Researchers are looking for additional genetic changes that contribute to septo-optic dysplasia.

Septo-optic dysplasia is usually sporadic, which means that the condition typically occurs in people with no history of the disorder in their family.

Less commonly, septo-optic dysplasia has been found to run in families. Most familial cases appear to have an autosomal recessive pattern of inheritance, which means that both copies of an associated gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. In a few affected families, the disorder has had an autosomal dominant pattern of inheritance, which means one copy of an altered gene in each cell is sufficient to cause the condition.

Yes, anosmia has been associated with this condition. Septo-optic dysplasia is a clinically diverse condition. In addition to the characteristic findings of optic nerve hypoplasia, pituitary hormone abnormalities and midline brain malformations, many patients have associated findings. In addition to the symptoms mentioned above, individuals with septo-optic dysplasia may have anosmia, diabetes insipidus, sleep disorders, autism spectrum disorders, precocious puberty, obesity, temperature regulation issues, sensorineural hearing loss, and birth defects affecting the heart, hands, and feet.

While limited information is available on this topic, one recent study found that children with septo-optic dysplasia are at an increased risk for having social, communication, and repetitive/restrictive behavioral difficulties. The following characteristics have been described as being common among children with septo-optic dysplasia, especially among those with severe vision loss:

Moderate to severe delays in information processing
Extreme tactual and auditory defensiveness
Difficulty with transitions
Rigid adherence to routine
Strong interest in rhythms and music
Restricted food preferences and eating problems related to an aversion to textured foods
Avoidance of social interaction and engagement
Profound distractibility
Mild hypotonia (low muscle tone)
Developmental delays in motor functioning
Lack of initiative in exploring their environments
Atypical language development
Enjoyment of swinging
Lack of spontaneity in verbal interactions

The prognosis for individuals with septo-optic dysplasia varies according to the presence and severity of symptoms. Early diagnosis and treatment of hormone deficiencies (when present) allows for a better outcome for some associated symptoms.

Treatment is directed toward the specific symptoms in each individual and may require a team of specialists including pediatricians, ophthalmologists, neurologists, and endocrinologists. If present, hormone deficiencies may be treated with hormone replacement therapy. Vision problems are generally not treatable. Special services that may be useful include vision, physical, and occupational therapies.