ABSTRACT
<p><b>OBJECTIVE</b>The frequency of the 22q11.2 deletion syndrome is increasing worldwide. The cardiovascular anomalies are one of the most frequent clinical manifestations in this syndrome. This study was designed to determine the frequency of 22q11.2 deletions in a prospectively ascertained sample from children with isolated conotruncal defects in China.</p><p><b>METHODS</b>Twenty-four children with isolated conotruncal defects were prospectively enrolled and screened for the presence of 22q11.2 deletions using fluoresence in situ hybridization. The 24 patients consisted of two cases of persistent truncus arteriosus (PTA), five cases of pulmonary atresia/ventricular septal defect (PA/VSD), thirteen cases of tetralogy of Fallot (TOF), and four cases of double outlet right ventricle (DORV).</p><p><b>RESULTS</b>Only 1 of the 24 patients had 22 q11.2 deletions. The frequency of 22q11.2 deletions (4.2%) was lower than that reported by other authors.</p><p><b>CONCLUSIONS</b>Although 22q11.2 deletion is common in syndromic conotruncal anomalies, it is rare in isolated conotruncal anomalies.</p>