What Is Möbius Syndrome?

Möbius syndrome is a rare disease, although it appears to be on the rise. Recent congresses of neurology and ophthalmology report that there has been an increase in registered cases of Möbius syndrome.

It can be said that one of the main features of Möbius syndrome is the inability to smile. Although people with this syndrome experience happy situations and would like to smile, they are unable to do so.

However, not smiling is not the only feature. The sufferer of this rare disease is unable to make many of the usual facial expressions. For example, the syndrome affects the ability to move the eyes from side to side.

This is because two pairs of cerebral nerves – numbers six and seven – are partially or completely undeveloped. These nerves control the muscles involved in mimicry and are part of the muscles that perform some of the eye movements. 

As we will see later in this article, all brain nerve pairs have their own specific functions. The brain nerve pair number six regulates the lateral movement of the eyes. The brain nerve pair number seven is called the “facial nerve” because it controls facial expressions.

Möbius syndrome is such a rare disease that only one member of the family can have it. It is estimated that one in 120,000 people has this disease.

What are cerebral nerves?

To better understand the symptoms of Möbius syndrome, it is good to know the brain nerve pairs and their function.

• The optic nerve  is the optic nerve.
• The trigeminal cerebral nerve is associated with chewing.
• The olfactory cerebral nerve carries information about the detection of odors.
• The hypoglossal cerebral nerve nerves the muscles of the tongue and neck.
• The auditory brain nerve carries the information we hear to the brain.

• The glossopharyngeal cerebral nerve transmits taste information obtained through the tongue.
• The pathetic cerebral nerve nerves the muscles involved in eye movements.
• The external ocular motor nerve is the nerve most affected by Möbius syndrome.
• The facial cerebral nerve is another nerve that is strongly affected by this disease.
• The vagus nerve expands outside the skull, reaching the thoracic and abdominal areas.
• The Acessorius nerve also expands outside the skull into the muscles of the neck and back.
• The oculomotor cerebral nerve is the third cerebral nerve that nerves some of the muscles involved in eye movements.

Etiology of Möbius syndrome

It is important to clarify that while Möbius syndrome is referred to as a syndrome, it is not. Möbius is known in genetics as a sequence. Sequences may have multiple deformations simultaneously originating from a single anomaly.

In the case of Möbius, the anomaly is due to the immature or total absence of nerve nuclei number six and seven in the brain nerve pairs. Imaging examinations of patients and autopsies have led to the same diagnosis.

The etiology of the disease is not always genetic. There have also been cases where cerebral nerve problems have been caused by medication. Misoprostol is a drug that is most often associated with this disease, as shown by a group study at the Universidad del Norte in Barranquilla, Colombia.

This medicine is usually used as an abortifacient medicine. If the drug fails in this task, the fetus may develop Möbius syndrome. 

Symptoms of Möbius syndrome

Newborns with Möbius syndrome may have difficulty breathing in addition to the absence of facial expressions. The baby may drool excessively and his or her muscle tone is poor, which can affect the child’s walking.

In such a case, the person may experience deformities of the legs, which may delay learning to walk. Other reported symptoms associated with the disease include:

• tapered palate
• absence of eyelids
• hypersensitivity to sunlight and other strong lights
• hearing problems due to fluid buildup in the inner and middle ear

Experimental methods of treatment

There is no cure for Möbius syndrome. So it is not completely manageable. Facial rehabilitation treatments have not been shown to be effective.

However, there is experimental surgical treatment that originated in Canada. In this surgery, a muscle transplant is performed on the facial area to make it possible to smile in the future.

It has been estimated that surgery can produce the best possible result when the patient is about five years old. While this practice is promising, it is not available worldwide and is prohibitively expensive.

Families with Möbius syndrome often have to fight discrimination. For this reason, they want to raise awareness of the disease among the public, emphasizing that these patients also have emotions, even if they are unable to express them with facial expressions.

The treatments are still in the experimental phase in the medical world. However, the prognosis for surgical procedures is promising. It is important to respect those with Möbius syndrome and to understand that their inclusion in social life depends on better awareness of this disease.