Deafness may be sensorineural, conductive, or
mixed. The neck has a webbed appearance, and there is a variable degree of
cervical fusion (Klippel-Feil syndrome). Abducens nerve palsy with globe
retraction on looking medially is present (Duane retraction syndrome).
Additional abnormalities may include short stature, microcephaly,
hydrocephalus, brainstem and cerebellar hypoplasia, occipital meningocele,
structural facial asymmetry, facial palsy, strabismus, cleft palate,
scoliosis, Sprengel deformity (elevated, hypoplastic scapula), spina bifida,
preauricular, tags and pseudopapilledema. One case report describes
Diastematomyelia of the lower medulla and cervical cord that was accompanied
by vermian hypoplasia and tonsillar herniation of the cerebellum resulting in triventricular
hydrocephalus. Cardiac defects such as atrial and/or ventricular septal
defects may be present. Intelligence usually is normal, but some patients
with mental retardation have been reported.