Prenatal Ultrasound Diagnosis and Genetic Analysis of Interrupted Aortic Arch

This study aims to classify fetal interrupted aortic arch (IAA) and its associated intracardiac and extracardiac malformations. Additionally, it seeks to summarize the genetic characteristics of IAA fetuses through copy number variation sequencing (CNV-seq) and whole exome sequencing (WES).

We conducted a retrospective analysis of 156 fetuses diagnosed with IAA via fetal echocardiography at Beijing Anzhen Hospital, Capital Medical University, between August 2010 and December 2023. Of these, 24 cases underwent genetic testing. Ultrasound images from these cases were analyzed to determine the type of IAA and to assess associated intracardiac and extracardiac malformations. Genetic abnormalities were evaluated using CNV-seq and WES.

Among the 24 IAA cases, 8 (8/24, 33.3%) were classified as Type A IAA, while 16 (16/24, 66.7%) were classified as Type B IAA. All cases exhibited associated malformations, with 18 (18/24, 75.0%) presenting solely with intracardiac defects and 6 (6/24, 25.0%) exhibiting both intracardiac and extracardiac defects. Of the 24 cases undergoing CNV-seq and WES, 12 (12/24, 50.0%) yielded positive genetic findings. The detection rate for fetuses with only intracardiac malformations was 33.3% (6/18), whereas it was 100.0% (6/6) for those with extracardiac malformations. Positive findings included three cases (3/12, 25.0%) of aneuploidy, six cases (6/12, 50.0%) of copy number variation (CNV), and three cases (3/12, 25.0%) of single nucleotide variants (SNVs).

This single-center study found that all IAA fetuses were associated with cardiac malformations, with a significant likelihood of concurrent extracardiac anomalies. The prevalence of genetic abnormalities was notably high, particularly for CNV. Therefore, prenatal imaging indicating IAA strongly recommends further genetic testing using CNV-seq and WES.