Clinical relevance of monosomy 22q11.2 in children with pulmonary atresia and ventricular septal defect

The purpose of our study was to describe the prevalence and the clinical sp ectrum of monosomy 22q11.2 in a population of patients with pulmonary atres ia and ventricular septal defect. We examined all 44 patients with this con otruncal cardiac malformation who presented to our institution from January 1994 until December 1997. The type of collateral lung perfusion was record ed including anomalies of the pulmonary arteries as well as facial and immu nological abnormalities. Molecular-cytogenetic testing for a 22q11.2 microd eletion was per-Formed using the probes D22S75 and cHKAD26. Statistical dif ferences were evaluated with the Fisher's Exact Test. Monosomy 22q11.2 was present in ten children (23%) with major aortopulmonary collateral arteries (group 1). The remaining 13 children (29%) with major aortopulmonary colla teral arteries (group 2) and all 21 children (48%) with ductus arteriosus ( group 3) were negative For this microdeletion. All children in group 1 had facial anomalies, six had mild immunological abnormalities including decrea sed CD 4+ or CD 8+ cells. Anomalies of the pulmonary vascular bed were sign ificantly more frequent in children of group 1 (9/10) than in children of g roup 2 (4/13) or group 3 (0/21). Due to these pulmonary vascular anomalies, corrective surgery had been accomplished in fewer children with monosomy 2 2q11.2 (none in group I) as compared to 7/13 children in group 2 and 14/21 children in group 3. Conclusion In children with pulmonary atresia and vent ricular septal defect; monosomy 22q11.2 is preferentially associated with m ajor :aortapulmonary collateral arteries, Due to the higher incidence of pu lmonary arterial abnormalities, successful surgical repair will require a d ifferent therapeutic approach in most patients with this microdeletion.