The radiological pattern associated with the trisomy of the short arm of chromosome No 4.

A fairly constant constellation of roentgen anomalies has been detected in the skeleton of 9 patients with the trisomy of the short arm of chromosome No 4. The more common changes involve the skull, spine and pelvis, while the limbs, as well as the internal organs, are less affected. Microcephaly, hypertelorism, small and closed sella, malocclusion, scoliosis, "square" vertebral bodies, narrow iliac wings, wide iliac angles and narrow acetabular ones, coxa valga, medial recumbency of the proximal tibial epiphysis and retarded bone age are usual findings.