Ossification centre of the hyoid bone in DiGeorge syndrome and tetralogy of Fallot.

The incidence of radiographic visibility of the ossification centre of the body of the hyoid bone in radiographs taken during the first month of life was analysed for 34 autopsied infants: 16 with DiGeorge syndrome (DGS), 14 with tetralogy of Fallot (TOF), four with interrupted aortic arch (IAA) and a further 13, surviving infants with non-DGS TOF or non-DGS IAA. The incidence of visible hyoid ossification centre (HOC) was 75.7% in a control series of infants with neither congenital heart disease (CHD) nor DGS. Autopsied patients with DGS, TOF without DGS, and IAA without DGS showed a significantly low incidence of visible HOC. Infants with TOF (and possibly those with IAA) who did not have DGS and who did not die during infancy showed a normal incidence of visible HOC in radiographs taken during the first post-natal month. Radiological visibility of the HOC in the first post-natal month appears useful in the diagnosis of DGS and forms of CHD often seen in association with DGS and in assessing prognosis of neonates with certain types of CHD.