Genetic Ethiology, Associated Anomalies in Fetal Aberrant Right Subclavian Artery: A Retrospective Cohort Study in a Tertiary Hospital

INTRODUCTION: This study aimed to determine the prevalence of chromosomal anomalies in fetuses with isolated and non-isolated aberrant right subclavian artery (ARSA) and to evaluate its association with other congenital anomalies.
METHODS: From 1 June 2021 to 1 June 2023, 47 ARSA cases were diagnosed by prenatal ultrasound in our hospital. The fetuses were divided into isolated ARSA group and non-isolated ARSA group. Among the 47 fetuses, 15 were characterized in the isolated group and 32 with combined other ultrasonic abnormalities in the non-isolated group. General information, ultrasound presentation, chromosomal findings, and birth and pregnancy outcomes were reviewed retrospectively.
RESULTS: In the non-isolated ARSA group, 17 cases (53,1%, 17/32) were associated with congenital heart defects, and 8 cases (25 %, 8/32) were associated with extracardiac abnormalities. Chromosome karyotype analysis was performed successfully with all 23 samples, and a total of 8 abnormalities (17 %, 8/47) were detected, including 7 cases of trisomy 21, and 1 case of trisomy 18. Single-nucleotide polymorphism array was performed in these 5 cases. Microdeletion was detected in four cases, but one of the arrays was reported normal. Using SNP-array and karyotype analysis in fetuses with ARSA, the total chromosomal anomaly detection rate was found 25.5 % (12/47).
DISCUSSION AND CONCLUSION: The most common malformation accompanying ARSA is cardiac abnormality. Isolated ARSA has a low risk of chromosomal abnormalities, so invasive chromosomal testing is not recommended. Non-isolated ARSA has a high incidence of chromosomal abnormalities, so early karyotyping should be recommended.