Ventricular septal defect associated with microdeletions of chromosome 22q11.2

Microdeletions of chromosome 22q11.2 (del.22q11) cause DiGeorge syndrome, velo-cardio-facial syndrome, and conotruncal anomaly face syndrome, which are commonly associated with conotruncal heart anomalies. Approximately 15% of the patients manifest ventricular septal defects (VSD), and the conal-septal type of VSD has been proposed to be associated with del.22q11, since it is categorized as a conotruncal anomaly. However, the types of VSD associated with del.22q11 remain poorly studied. The purpose of this study is to assess whether conal-septal VSD or other types of VSDs are associated with del.22q11. We analyzed the chromosomes of 22 consecutive patients with conal-septal VSD, prospectively, and evaluated the types of VSD observed in 3 patients with del.22q11, retrospectively. Del.22q11 was not detected in any of the 22 patients with conal-septal VSD. All the VSDs observed in the 3 patients with del.22q11 were a perimembranous type of VSD, which is not a conotruncal anomaly. Our results suggest that perimembranous VSD can be associated with del.22q11, but del.22q11 is not a common cause of conal-septal VSD.