Moebius Syndrome

Synonym: Mobius sequence/syndrome (Congenital facial diplegia)

This is a complex developmental disorder of the brainstem, where there is a congenital facial palsy (usually bilateral) in association with impairment in abduction of the eyes (also usually bilateral).¹ As well as involving the facial (VII) and abducens nerves(VI), other cranial nerves can be involved.

Other associated abnormalities¹

• Orofacial dysmorphism: micrognathia (64% of patients), ocular hypertelorism (25%), epicanthal folds (89%), external ear defects (47%), high-arched palate (61%) tongue hypoplasia (77%), teeth defects (37%)
• Limb malformations (syndactyly, oligodactyly, brachydactyly, arthrogryposis, absent trapezius or pectoral muscles, lower limb deformities in 69% e.g. club foot)
• Mental retardation (IQ low in 50%)
• Hypotonia, pharyngeal weakness, feeding difficulties
• Respiratory difficulties in infancy
• Delayed developmental milestones

Most cases are sporadic mutations, but an autosomal dominant transmission has been described (chromosome 13).¹ Misoprostol, ergotamine, and chorionic villus sampling have been suggested as possible environmental factors.²