Congenital perceptive deafness is due to a bony malformation of the inner ear. A Klippel-Feil cervical malformation consisting of a low hairline, limited neck mobility, and short neck secondary to cervical fusion (usually involving the atlas and axis) is present as well. The presence of neck webbing (pterygium colli) can exaggerates the short neck appearance. Diastematomyelia of the lower medulla and cervical cord has been reported in a child who also had tonsillar herniation and hydrocephalus of all three ventricles.
A variety of inconsistent anomalies including spine deformities, cardiac malformations, anomalies of the genitourinary system and somatic growth retardation have also been reported.
The KFS malformation can occur alone or in association with other syndromes.
