Thyroid gland and carotid artery anomalies in 22q11.2 deletion syndromes

Abstract

Chromosome 22q11.2 deletion syndromes (22q11DS), such as velocardiofacial syndrome and DiGeorge syndrome demonstrate developmental anomalies affecting the branchial arch structures. Mouse models have shown abnormalities of both the thyroid gland and the common carotid arteries and have suggested a developmental link between the two structures. Here we examine radiological abnormalities of the carotid artery bifurcation and thyroid gland. Retrospective case control study. We reviewed multiplanar contrast-enhanced computed tomography scans with 3-D reformats of 66 children falling into three groups: 1) children with velopharyngeal insufficiency testing positive for 22q11DS (n = 28), 2) children with velopharyngeal insufficiency testing negative for 22q11DS (n = 10), and 3) age and gender matched controls (n = 28). The common carotid bifurcations were measured according to cervical spinal (C-spine) level. The thyroid gland morphology was also assessed. The 22q11DS group demonstrated lower overall common carotid bifurcations. The median C-spine level of bifurcation was significantly different in the 22q11DS group compared to controls on the right (5 vs. 3.; P < .01) and left (6.5 vs. 3.25; P < .001). These patients demonstrated asymmetry when comparing the bifurcations between sides. Fourteen of 28 patients (50%) with 22q11 deletions demonstrated at least one of four different thyroid anomalies. Anomalies included absence of a lobe, absence of the isthmus, retrocarotid, or retroesophageal extension. The 22q11DS group had significantly higher proportions of thyroid abnormalities compared to the control groups (P < .01). Patients with 22q11DS demonstrate statistically significantly lower carotid artery bifurcations and a higher proportion of radiological thyroid abnormalities.