Absent or hypoplastic thymus on ultrasound: a marker for deletion 22q11.2 in fetal cardiac defects

• DOI: 10.1046/j.1469-0705.2002.00864.x
• Publication Date: 2003-05-21T13:07:57Z
• Authors: R. Chaoui; K. D. Kalache; K. S. Heling; C. Tennstedt; C. Bommer; H. Körner
• Keywords: Truncus arteriosus; DiGeorge syndrome; Interrupted aortic arch; Pulmonary atresia; Fetal echocardiography; Aplasia; Truncus

Abstract Objective Congenital heart defects (CHD), particularly conotruncal anomalies, may be associated with deletion of chromosome 22q11.2. Thymic aplasia or hypoplasia is known to a typical feature in this condition. We aimed establish (i) the prevalence del22q11.2 fetal CHD and (ii) whether ultrasound assessment an absent hypoplastic thymus helps preselection group who are at high risk for deletion. Study design In fetuses (> 16 weeks) CHD, karyotyping fluorescence situ hybridization 22q11.2 were offered was evaluated sonographically. Results One hundred forty‐nine normal karyotype analyzed. Seventy‐six had anomalies. present 10 cases (6.7%), all which anomalies (13.1%). absence suspected 11 anomaly. Nine these deletion; two false positive. fetus normal‐sized (sensitivity 90%, specificity 98.5%, positive predictive value 81.8%, negative 99.2%). By subtype cardiac anomaly, there four six interruption aortic arch, pulmonary valve syndrome, three nine truncus arteriosus one tetralogy Fallot. Pulmonary atresia ventricular septal defect ( n = 7), right‐sided arch 4), transposition great arteries 14), double outlet right ventricle 13) other complex malpositions vessels 8) not Conclusion reliably diagnosed during echocardiography. The technique allows identification more specific sensitive than by anomaly alone. Copyright © 2002 International Society Ultrasound Obstetrics Gynecology