Abstract
First described in 1999, 22q11.2 duplication syndrome has a phenotype similar to that of 22q11.2 deletion syndrome. We present a case of 22q11.2 duplication diagnosed by fluorescence in situ hybridization (FISH) analysis performed to screen the genetic background of a rare congenital vascular anomaly, persistent 5th aortic arch. This male infant was born at 36 weeks of gestation with a birth weight of 1,770 g. Dysmorphic facial features were noted, and echocardiography revealed ventricular septal defect, atrial septal defect, persistent 5th aortic arch, aberrant right subclavian artery, and persistent left superior vena cava. Ligation of the ductus arteriosus was performed at age 13 days. Comparative genomic hybridization (CGH) microarray analysis revealed that the duplication was located at a typical 3-Mb region. Although persistent 5th aortic arch has been reported in patients with 22q11.2 deletion, this is the first case of 22q11.2 duplication complicated by 5th aortic arch. This case demonstrated that a gene dosage effect involving 22q11.2 could contribute to the development of persistent 5th aortic arch.
