Adequate tracheas from 6 of 14 patients with DiGeorge syndrome (2 complete and 4 partial forms) were available for tracheal ring study. The number of tracheal rings in these patients was significantly low (mean ± SD 14.7 ± 1.4). This is consistent with an effect of deficient blood supply to the fetal cervical region, a mechanism that has been proposed to explain the defective development of thymus and parathyroid glands in DiGeorge syndrome. To our knowledge this lesion has not been described as one of the malformations found in the syndrome.

In 8 of 14 (57%) patients with DiGeorge syndrome, common origin of the carotid arteries was found, and 4 of these 8 patients showed minor tracheal compression. These findings support the proposal that abnormal blood supply to the region of the third and fourth pharyngeal arches may play a role in the pathogenesis of DiGeorge syndrome.