An über rare autosomal dominant condition (OMIM:157900) characterised by congenital paralysis of cranial nerves 6 and 7, occasionally also of cranial nerves 5 and 8. It may be associated with other orofacial–e.g., strabismus, corneal erosion due to lack of blinking, limb–e.g., club feet, agenesis of fingers or toes, musculoskeletal–e.g., Poland syndrome, dyspnoea, dysphagia–defects, and pseudomental retardation–due to expressionless facies, strabismus, and frequent drooling.
This condition was defined at the Moebius Syndrome Foundation Research Conference in 2007 as congenital, nonprogressive facial weakness with limited abduction of one or both eyes. Additional features can include hearing loss and other cranial nerve dysfunction, as well as motor, orofacial, musculoskeletal, neurodevelopmental, and social problems.
Risk factors Uncertain; possibly intrauterine hypoxia; failed termination of pregnancy with misoprotol, and cocaine use during pregnancy may markedly increase the baseline risk (1:50,000-100,000) of Moebius syndrome.
Management Little can be done for the disease. So-called smile surgery in which muscles are transposed to the face may provide some semblance of facial expression.
Molecular pathology Defects in MBS1–chromosome 13q12.2, MBS2–chromosome 3q21-22, MBS3–chromosome 10q21.3-q22.1 cause Moebius syndrome. The function of these genes is currently unknown.
A Möbius strip or band (above image) is a surface with only one side and only one boundary component.
Synonyms Akinesia algera, congenital abducens facial paralysis, congenital bulbar paralysis, congenital facial diplegia, congenital nuclear agenesis, congenital nuclear aplasia, congenital oculofacial paralysis, congenital paralysis of horizontal gaze, congenital paralysis of the sixth and seventh nerves, infantile nuclear paralysis, Mobius syndrome, Moebius anomalad, Moebius sequence, Möbius sequence, Moebius II syndrome, nuclear agenesis, oculofacial paralysis, von Graefe’s syndrome