The most characteristic clinical finding is the
presence of short stature with a disproportionate short trunk (thorax). The
association of odontoid hypoplasia causing cervical spine instability and
the failure of normal segmentation of the thoracic vertebrae resulting in
fused segment of the spine (unilateral segmented bar) are characteristic of
this syndrome. This anatomical problem leads to severe scoliosis or
lordosis. The fused spine is difficult to identify in early childhood since
the ossification of the vertebrae is not complete. Most patients have a
broad and round face, cleft palate, enamel hypoplasia, sensorineural hearing
loss, preauricular skin tag, hypertelorism, cataracts, retinal pigmentation,
and narrow retinal vessels. Other clinical features include postaxial polydactyly,
decreased range of motion of elbows, and the presence of pes planus.