Moebius syndrome

Moebius syndrome is a very rare, congenital (present at birth) type of facial nerve palsy. The disorder occurs when the sixth and seventh cranial nerves — two nerves that grow out of the brain and control the sideways movements of the eyes and the movements of the facial muscles, respectively – are either improperly formed or missing altogether.

Named after the neurologist who first discovered it in the late 19^th century, Moebius syndrome (which is also sometimes spelled “Möbius syndrome”) causes an inability to:

• suck while nursing
• smile or frown
• use the eyes to automatically track objects or motion, without having to turn the head

In addition, children with Moebius syndrome usually have:

• crossed eyes
• difficulty blinking
• weak muscle tone (especially in the upper body)

More rarely, a child with Moebius syndrome may also experience:

• some degree of intellectual disability or developmental delay
• other physical problems, such as limb deformities, respiratory illnesses or mouth, tongue and jaw deformities

While there is no known cure for Moebius syndrome, new advances make it possible to manage most children’s symptoms and complications very well.

Children’s Hospital Boston is home to a multidisciplinary Facial Reanimation Program that is devoted to Moebius syndrome and other disorders that cause facial paralysis. Our expert clinicians will make a comprehensive diagnosis and advise you on the best treatment plan for your child’s individual symptoms and circumstances. At the same time, we will provide you with a wide range of support services to meet the needs of your entire family.

Causes 

What causes Moebius syndrome?
Although we still don’t understand precisely what causes Moebius syndrome, two factors are thought to play a role:

Disrupted blood flow in the brain
Experts believe that disruption to the blood flow in a fetus’s brain may be responsible for Moebius syndrome. However, it is not known exactly what mechanism is involved in the disrupted blood flow, nor how it interrupts (or prevents) the development of the sixth and seventh cranial nerves.

Exposures during pregnancy
Moebius syndrome may be linked to a mother taking certain drugs during her pregnancy, such as:

• Thalidomide, which is used to treat the blood cancer multiple myeloma in some patients
• Misoprostol, which is used for several medical purposes (ranging from treating a particular type of ulcer to inducing labor)
• cocaine

Is Moebius syndrome ever inherited?
Research has revealed possible genetic ties in some families, but these instances are very rare. In nearly every family affected by Moebius syndrome, only one person in that family has the disease.

Scientists have not yet been able to identify a particular gene responsible for Moebius.

Signs and symptoms

What are the first symptoms of Moebius syndrome in a newborn?
The first sign of Moebius syndrome in newborns is an inability to suck, sometimes accompanied by excessive drooling and crossed eyes.

Less often, babies with Moebius syndrome will also have deformities of the limbs (such as clubfoot), tongue, jaws or mouth.

What are some other symptoms to look out for as my child ages?
As she grows, a child with Moebius syndrome will demonstrate difficulty blinking and a noticeable lack of facial expressions, including:

• smiling
• frowning
• squinting

It is also possible that she may experience:

• weak muscle tone (especially in her upper body); this can make it challenging for her to crawl or sit up
• heightened sensitivity to bright lights and loud sounds
• limited ability to move her tongue
• a buildup of fluid in her ears (causing some degree of hearing loss)
• dental problems
• speech problems
• frequent respiratory illnesses
   

FAQ 

Q: Will my child be OK?
A: Most likely, yes. Although Moebius syndrome does cause some difficulty in communication for all children – and can cause vision, nutrition, learning and dental issues for some – it is not a life-threatening condition, and can be managed very well with the right tools and treatment approach.

Q: How common is Moebius syndrome?
A: Available data is scarce, but we know the disorder is very rare: According to the National Institutes of Health, anywhere between 1 in 50,000 and 1 in 500,000 newborns have Moebius syndrome.

Q: Is Moebius syndrome always obvious at birth?
A: The condition is always present at birth, and is usually evident right away because the baby cannot suck during nursing (and may also drool excessively and have visibly crossed eyes).

Sometimes, Moebius syndrome is not diagnosed until the baby is older, when her lack of facial expressions becomes more noticeable.

Q: Does Moebius syndrome cause intellectual disabilities or developmental delays?
A: Sometimes, but not always. Many children with Moebius syndrome have normal intelligence and hit their developmental milestones right on time. However, other children with the disease do have intellectual disabilities or some developmental impairment.

Q: What other complications can occur with Moebius syndrome?
A: Not every child with Moebius syndrome will have other physical problems. When they do occur, secondary conditions usually include one or more of the following:

• deformities of the mouth, jaw or tongue
• respiratory problems
• limb deformities, such as clubfoot

Q: Is there any way to prevent Moebius syndrome?
A: Since there is no proven cause of Moebius syndrome, there is no guaranteed way to prevent the disorder.

However, there is evidence that certain drugs taken during pregnancy might be linked to the onset of Moebius in some cases. As a precaution, pregnant women should avoid taking:

• Thalidomide, which is used to treat the blood cancer multiple myeloma in some patients
• Misoprostol, which is used for several medical purposes (ranging from treating a particular type of ulcer to inducing labor)
• cocaine

Q: Can Moebius syndrome be detected during pregnancy?
A: No. Because Moebius syndrome affects facial expressions and movements – and prenatal screening cannot detect these nuances – the disorder does not show up reliably on prenatal ultrasounds.

Q: If my child has Moebius syndrome, do I need to be screened before any future pregnancies?
A: Most cases of Moebius syndrome are sporadic, meaning they occur only once in a family, with a very slight chance of occurring again.

Although there is a small number of families in which more than one person has Moebius syndrome, it is impossible to screen for the disease; researchers have not been able to identify any particular gene that is responsible.

Q: Is there a cure for Moebius syndrome?
A: Unfortunately, no. Treatment for Moebius syndrome centers on managing symptoms, but there is no approach that serves as a permanent cure.

Q: Can my child enjoy a good quality of life without being able to make normal facial expressions?
A: Yes. Although the inability to produce a full range of facial expressions does pose challenges – particularly when it comes to interpersonal communication and socializing – support services like speech therapy and counseling can help your child develop valuable tools for leading a rich, active life at school, at home and with friends.

Questions to ask your doctor

You and your family play an essential role in your child’s treatment for Moebius syndrome. It’s important that you share your observations and ideas with your child’s treating physician, and that you have all the information you need to fully understand the treatment team’s explanations and recommendations.

You’ve probably thought of many questions to ask about your child’s symptoms and prognosis. It’s often very helpful to jot down your thoughts and questions ahead of time and bring them with you, along with a notebook, to your child’s appointment. That way, you will have all of your questions in front of you when you meet with your child’s treating clinician and can make notes to take home with you.
 
Initial questions to ask your doctor might include: 

• How did you arrive at this diagnosis?
• Are there any other conditions my child might have in addition to, or instead of, Moebius syndrome?
• Does my child require further testing or procedures?
• Does he have any related intellectual disability or developmental delays?
• Does he have any accompanying vision, hearing or dental/orthodontic problems?
• What medications will you prescribe and what are the possible side effects?
• What role should speech therapy play in his care?
• Do you recommend counseling?
• Does he need surgery? If so, what procedure(s) do you recommend and what will it entail?
• What adjustments need to be made in his home and school routines?
• How should I talk about my child’s condition with him as he gets older?
• How should I explain my child’s condition to others?
• What other resources can you point me to for more information?