Moebius Syndrome or Moebius Disorder (MBS) is a rare neurological disorder that affects the muscles of facial expression and eye movement. It is diagnosed during infancy.
The cause of MBS remains controversial and the condition is determined genetically. It is characterized by loss of motion (paralysis) of numerous cranial nerves, most frequently, the sixth (abducens) and seventh (facial) nerves. Other cranial nerves may also be affected.
A person with MBS can not smile, frown, pucker the lips, raise the eyebrows, or close the eyelids. This is described as a "mask-like face". When the sixth (abucens) cranial nerve is affected, the eye can not turn outwards away from the midline.
Other symptoms associated with MBS include skeletal malformations such as underdeveloped legs, clubbed feet, webbed fingers, underdeveloped fingers or absence of fingers. Dental abnormalities such as small jaw and a short tongue could also be seen.