(1) The characteristic findings are mental retardation, characteristic facies, narrow forehead, bushy eyebrows with synophrys, hypertelorism, broad nose, wide philtrum, triangular-shaped mouth, short neck, marked maxillary hypoplasia, a low hairline (especially posteriorly in the midline on the neck), brachycephaly, calcified clinoid ligements, and multiple bony abnormalities in the upper thoracic vertebrae and sometimes in the cervical region, together with a variety of deformities of the upper ribs.
(2) The author reports a case due to rupture of the posterior ligements, without vertebral displacement on the first films, but which became complicated secondarily by dislocation, which it was necessary to reduce by open operation.