Relation of genotype 22q11 deletion to phenotype of pulmonary vessels in tetralogy of Fallot and pulmonary atresia-ventricular septal defect

摘要

Objective—To compare the morphology of the pulmonary vessels in tetralogy of Fallot or pulmonary atresia-ventricular septal defect (PA-VSD) with (del22q) and without 22q11 deletion (non-del22q).
Patients—94 consecutive infants (54 with tetralogy of Fallot, 40 with PA-VSD) were studied using ultrasound and catheterisation.
Molecular investigations—Identification of the 22q deletion was performed either by fluorescent in situ hybridisation or polymerisation chain reaction genotyping.
Results—25 patients were del22q (16/40 (40%) PA-VSD v 9/54 (17%) tetralogy of Fallot; p < 0.02). Major aortopulmonary collateral arteries was more common in patients with PA-VSD-del22q (p < 0.03). Such collaterals were identified in 13 patients: 10 del22q and three non-del22q (p < 0.001). The size of the right and left pulmonary arteries expressed as a standard deviation (SD) difference of the normal range was −4.2 (quartiles −5.3 and −2.9) for PA-VSD del22q, and −2.6 (−3.1 and −1.8) for PA-VSD non-del22q (p = 0.02). The mean (SD) difference between the measured and theoretical Nakata index was −373 (94) for PA-VSD del22q v −245 (93) in PA-VSD non-del22q (p = 0.0002). In tetralogy of Fallot patients with and without del22q, the size of the pulmonary arteries was similar (p = 0.6).
Conclusions—A "specific" phenotype could be defined in patients with deletion: PA-VSD, major aortopulmonary collateral arteries with complex loop morphology, and small central pulmonary arteries. Differences in the morphology of the pulmonary vessels may indicate a different timing of the faulty developmental pathway in patients with and without 22q11 deletion.

Keywords: 22q deletion;  tetralogy of Fallot;  congenital heart disease