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


METHODS
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.
Chessa
M
M
Service de Cardiologie Pédiatrique, Hôpital Necker/Enfants Malades, Paris, France.
Butera
G
G
Bonhoeffer
P
P
Iserin
L
L
Kachaner
J
J
Lyonnet
S
S
Munnich
A
A
Sidi
D
D
Bonnet
D
D
D001011:Aorta / Q000000981:diagnostic imaging / Q000473:pathology*; D002892:Chromosomes, Human, Pair 22; D003097:Collateral Circulation; D017353:Gene Deletion; D006345:Heart Septal Defects, Ventricular / Q000000981:diagnostic imaging / Q000235:genetics / Q000473:pathology; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D011446:Prospective Studies; D011651:Pulmonary Artery / Q000000981:diagnostic imaging / Q000473:pathology*; D018633:Pulmonary Atresia / Q000000981:diagnostic imaging / Q000235:genetics / Q000473:pathology; D011667:Pulmonary Veins / Q000000981:diagnostic imaging / Q000473:pathology*; D011859:Radiography; D013771:Tetralogy of Fallot / Q000000981:diagnostic imaging / Q000235:genetics* / Q000473:pathology*; D014463:Ultrasonography