Septo-Optic Dysplasia - A Developmental Disorder

Introduction:

Septo-optic dysplasia is a developmental disorder that impacts the brain's early development, affecting the optic nerve, pituitary gland, and other parts that lead to disturbances in the eyes, hormones, muscle function, and learning abilities. Though the condition has been present since birth, symptoms start to appear only after a few years. Untreated cases can lead to hormonal imbalances, growth defects, developmental delays, or blindness.

What Are the Other Names of Septo-Optic Dysplasia?

The other names of septo-optic dysplasia include:

• SOD.

• De Morsier syndrome.

What Are the Characteristics of Septo-Optic Dysplasia?

Septo-optic dysplasia affects early brain development. Certain abnormalities occur in an affected child, that includes:

1. Optic Nerve Hypoplasia: The optic nerve connects and helps carry information from the eyes to the brain and enables proper vision; however, in children with SOD, the optic nerve is either very small or not fully developed, leading to vision problems or difficulty in eyeball movements.

2. Pituitary Hypoplasia: The pituitary gland, also called the "master gland," secretes various hormones that regulate different body functions. A deficiency in hormones affects many parts. Panhypopituitarism is a condition in which there is a complete absence of pituitary hormones causing symptoms like slow growth, low blood glucose levels, and abnormal sexual development.

3. Midline Abnormalities of the Brain: The right and left halves of the brain are separated by a band of tissue called the corpus callosum. Ventricles are the fluid-filled spaces in the brain, separated by structures called septum pellucidum. In children affected with SOD, these two important structures develop abnormally, causing defects. Based on the structures that fail to develop, problems in learning or other neurological complaints occur.

Two-thirds of children affected by SOD develop two of the above three characteristics, whereas one-third of them develop all three.

How Commonly Does Septo-Optic Dysplasia Occur?

Septo-optic dysplasia is a rare condition that occurs in 1 in 10,000 newborn babies. It occurs equally in both boys and girls.

Who Are at an Increased Risk for Septo-Optic Disorder?

The factors that increase the risk of developing septo-optic disorder include:

• Interrupted blood flow to the brain in the mother's womb.

• Viral infections affect either mother or the fetus.

• Being born to very young mothers.

• Certain medications, street drugs, or substances of abuse are used by the mother.

• A family history of the disorder.

What Are the Causes of Septo-Optic Dysplasia?

The exact cause of septo-optic dysplasia is unclear. However, researchers believe that both genetic and environmental factors have a role in causing the condition. HESX1, OTX2, and SOX2 are the genes that play a role in developing the eyes, pituitary gland, and critical structures of the brain, like the optic nerve. Mutations (changes) in these genes can alter the early development of the structures that cause abnormalities. These genetic changes are either passed down from parents to their children or can occur spontaneously in the mother's womb. Environmental factors can cause the condition due to effects from outside the body, like infections, medications, or substances used by the mother during pregnancy.

What Are the Symptoms of Septo-Optic Dysplasia?

There is a variation in the signs and symptoms in different children, as they depend on the structures involved. All the symptoms do not develop at birth, and some of them may start to show up a few years after birth.

Symptoms associated with optic nerve dysplasia include:

• Low vision or loss of vision in one or both eyes.

• Squint (inward or outward malalignment of the eyes).

• Ambylopia (a condition in which one eye's focus is weak compared to the other).

• Mydriasis (unusual widening of the eye pupils in response to even dim light).

• Strabismus (crossed eyes, in which the direction of one eye is different from the other).

• Nystagmus (involuntary side-to-side eye movements).

Symptoms associated with pituitary hypoplasia include:

• Abnormal sexual development leads to early or late puberty.

• Insufficient growth hormone, causing stunted growth.

• Anosmia (loss of smell).

• Hypoglycemia (low blood sugars).

• Hypotonia (low muscle tone).

• Obesity.

• Small penis.

• Problems with sleep.

• Hypothyroidism (a condition that causes a decrease in thyroid hormones in the blood).

• Jaundice (yellow discoloration of the skin and eyes).

• Diabetes insipidus (a condition in which a fluid imbalance in the body causes excessive thirst and frequent urination).

Symptoms associated with abnormal brain development include:

• Learning disabilities.

• Behavioral problems.

• Developmental delays in reaching milestones.

• Seizures.

• Cleft lip and palate (a condition in which there is an opening in the roof of the mouth and upper lip present since birth).

• Cerebral palsy (a group of disorders that affect balance, posture, and movement of various body parts).

• Improper development of the eye's sockets, upper jaw bone, and cheekbones.

How Is Septo-Optic Dysplasia Diagnosed?

Doctors can diagnose the condition within the first few days after birth if there are noticeable symptoms like problems with eye movement, abnormality in the facial features, or jaundice. They may also order the following tests to confirm the diagnosis, that includes:

1. Hormonal Tests: Blood hormone levels help assess the pituitary gland functioning, thyroid hormone levels, and cortisol levels.

2. Genetic Tests: Genetic testing may be advised before or after the birth of the babies if the condition runs in families.

3. Imaging Tests: Tests like CT (computerized tomography) and MRI (magnetic resonance imaging) help detect developmental issues in the brain.

4. Vision Tests: Vision tests and eyesight testing help us know about problems and abnormalities of eye movements.

How Is Septo-Optic Dysplasia Managed?

There is no proper cure for the condition. Treatment aims at managing the symptoms and preventing them from developing into more severe problems. A medical team consisting of pediatricians, endocrinologists, neurologists, and ophthalmologists must work together to help patients manage the condition. Also, the outcome of treatment is better when SOD is detected early.

The following treatments are advised for patients with SOD, which include:

• Hormone Replacement Therapy (HRT): HRT helps resolve problems related to growth and sexual development. Also, it reduces the risk of developing diabetes and obesity.

• Vision Therapy: Vision therapy helps children improve in focusing and eye movements. Vision aids like glasses or magnifiers can help children perform better at school.

• Speech Therapy: Speech improvement and improved language and communication skills are focused on during speech therapy.

• Physical Therapy: Physical therapy opts to improve the strength and functioning of muscles.

• Occupational Therapy: It guides the children to perform daily routine activities more efficiently.

Conclusion:

Septo-optic dysplasia is a rare condition that can affect children from birth. The life expectancy of the patients improves in case of less severe symptoms. Parents, caregivers, and doctors form an integral part of the support system that helps the child cope with the condition. Women with a family history of SOD must plan pregnancy accordingly and opt for a healthy lifestyle to reduce the risks of complications in the child. The outcome of the condition depends on early diagnosis and the start of treatment.