What is Moebius Syndrome?

Overview

Moebius syndrome is a rare neurological condition that is present at birth and is estimated to affect about 1 in every 50,000 live births. It is a type of facial paralysis that affects the muscles responsible for facial expressions and eye movements. Some individuals may have only mild facial weakness or difficulty with eye movements, while others may have more severe symptoms, affecting their ability to speak, eat, and breathe. Early diagnosis and intervention can help improve the quality of an affected person’s life.¹

Causes of moebius syndrome

Moebius syndrome can occur when cranial nerves that supply the facial muscles and the eyes (cranial nerves six and seven) aren't fully developed or don't exist at all. The condition can be either congenital or acquiredand the exact cause is still unknown. 

In some cases, Moebius syndrome may be caused by a genetic mutation that affects the development of the nerves that control facial movements.

Exposure to certain environmental factors during pregnancy, such as toxins or viruses, may increase the risk of developing these mutations.

Some researchers also report that Moebius syndrome may be caused by abnormalities in the blood vessels that supply the facial nerves.

Finally, Moebius syndrome may also be associated with other medical conditions, such as Poland syndrome or Charcot-Marie-Tooth disease.²

Signs and symptoms of moebius syndrome

Individuals with Moebius syndrome cannot move their facial muscles, making it difficult to smile, frown, or show other expressions.^1,3 They may also have difficulty with eye movements, such as blinking or moving their eyes from side to side. People with Moebius syndrome may also have other health problems, such as trouble speaking or eating. Intellectual disabilities or learning difficulties can also present in patients affected by Moebius syndrome. Key symptoms to look out for include:

• Inability to move their eyes laterally or side-to-side, which can cause problems with reading, depth perception, and eye-hand coordination
• Difficulty being nursed or taking a bottle due to weak facial muscles
• Moebius syndrome can affect the muscles used for speech, leading to difficulties with articulation and pronunciation
• Limb abnormalities, such as clubfoot or joint contractures
• A small percentage of individuals with Moebius syndrome may experience hearing loss due to abnormal development of the inner ear
• Dental development can be affected, causing problems with tooth eruption and dental occlusion

Management and treatment for moebius syndrome

Even though there is no cure for Moebius syndrome, there are ways to manage the syndrome  that can help ease symptoms and improve the quality of life. People with Moebius syndrome often need to receive care from more than one type of doctor, including neurologists, ophthalmologists, speech therapists, and occupational therapists. Some procedures commonly employed to treatMoebius syndrome include:

• Facial reanimation surgery involves transferring healthy muscles from other parts of the body to the face to improve facial symmetry and movement
• Orthodontic treatment can help correct dental abnormalities that are frequently associated with Moebius syndrome⁴
• Moebius syndrome often causes eye problems, including dry eyes, long-sightedness, and nystagmus. Ophthalmologists can help manage these symptoms with eye drops and spectacles
• Physical therapy can help improve muscle strength and function, as well as reduce joint stiffness and pain
• Occupational therapy can help individuals with Moebius syndrome develop skills to perform daily activities and improve their overall quality of life
• Speech therapy can help individuals with Moebius syndrome improve their speech and language skills, as well as their capability to swallow

FAQs

How is moebius syndrome diagnosed?

The diagnosis of Moebius syndrome requires a thorough evaluation by a healthcare provider and may involve a multidisciplinary team of specialists, including neurologists, geneticists, and ophthalmologists.¹ The diagnosis is generally made based on a combination of clinical features, a physical examination and the patient’s medical history. The doctor will perform a physical examination to look for signs and symptoms of Moebius syndrome, such as facial muscle weakness, impairments in eye movements and dental abnormalities. Imaging tests, like magnetic resonance imaging (MRI),  may be used to examine the brain and cranial nerves that control eye movements and facial expression. Genetic testing is done to identify any heritable mutations that can cause Moebius syndrome. Electromyography (EMG) measures the electrical impulses of muscles and can help determine the extent of muscle weakness in affected individuals.⁵

How can I prevent moebius syndrome?

There are actions that can be taken to reduce the risk of developing Moebius syndrome. Moebius syndrome is more likely to happen if a pregnant woman is exposed to certain poisons and medicines. Hence, avoiding exposure to dangerous substances, such as alcohol, tobacco, and certain medicines, can help reduce the chances that the infant will acquire the syndrome. Maintaining a healthy life during gestation and receiving proper antenatal care can also help reduce the threat of complications during gestation that may lead to the development of Moebius syndrome. If you have a family history of Moebius syndrome or other heritable diseases, consider speaking with a genetic counsellor before starting a family. They can help determine your risk of passing on the condition to your child and give guidance for family planning.

Who is at risk of moebius syndrome?

Certain factors have been associated with an increased risk of Moebius syndrome. Use of tobacco, alcohol and specific medication (like misoprostol) during gestation heightens the chance that the baby will be affected by the syndrome. Individuals who have relatives who suffer from Moebius syndrome are at a higher risk than usual of being affected as well. However, the mutations that have been associated with the syndrome can occur spontaneously, making those with no family history susceptible to Moebius syndrome.

How common is moebius syndrome?

Moebius syndrome is a collection of symptoms, primarily affecting the eyes and face, that occur very rarely. The exact frequency of the syndrome is unknown but estimates suggest that it affects anywhere between 2 to 20 people per one million, in the general population.

When should I see a doctor?

As Moebius syndrome is present at birth, the symptoms can be detected in infancy and addressed immediately.  Early diagnosis and treatment can help people with Moebius syndrome live longer and avoid complications. You can start by seeing a general practitioner who may then refer you to a specialist, such as a neurologist or geneticist, for further evaluation. The doctor will most likely conduct a physical examination and may order imaging and blood tests to help rule out other conditions. Symptoms of Moebius syndrome that are important to look out for can include::

• Lack of facial expressions
• Inability to smile 
• Difficulty closing or opening eyes
• Impaired eye movements
• Difficulty with speech and feeding
• Weakness, or palsy, of the facial muscles
• Abnormalities of the jaw and palate

Summary

Living with Moebius syndrome can be grueling, but with the right support and treatment, individuals with the condition can lead full and meaningful lives. Support groups and counselling is available to help individuals with Moebius syndrome, and their families, to connect with others who understand their condition. Moebius syndrome occurs in about 1 in every 50,000 live births. It is a type of facial paralysis that affects the muscles responsible for facial expressions and eye movements. The condition can be congenital or acquired but the exact cause of the syndrome is yet to be identified. There is no cure for Moebius syndrome but there are management and treatment options available to help alleviate symptoms and improve the quality of a patient’s life. These include physical therapy to improve motor skills, speech therapy to help with communication, and surgery to improve facial and eye movements. Maintaining a healthy life during gestation and receiving adequate antenatal care can help reduce the threat that an infant will develop the condition.