Association of aberrant right subclavian artery with abnormal karyotype and microarray results.

<bold>Objectives: </bold>The objective of this study is to evaluate the incidence of chromosomal aberration (both microscopic and sub-microscopic) in fetuses with an aberrant right subclavian artery (ARSA) detected by ultrasonographic anomaly scan.<bold>Methods: </bold>The study included 62 pregnant women whose fetuses were diagnosed with ARSA who were referred for genetic counseling. Of these, 55 patients underwent amniocentesis and 7 declined invasive testing. All 55 amniocentesis samples were tested by standard G-banding and chromosomal microarray, except for 2 samples for which only karyotype and fluorescence in situ hybridization for 22q11.2 deletions were performed.<bold>Results: </bold>Of the 55 women who underwent amniocentesis, 5 were detected with trisomy 21 (9.1%), all of whom had additional ultrasound findings. Among the 14 fetuses with ARSA and additional ultrasound findings, the incidence of trisomy 21 was 35.7%. In fetuses with isolated ARSA, no chromosomal aberrations were detected by standard cytogenetic analysis and only one (1.9%) deleterious copy number variants (CNV) was detected by chromosomal microarray.<bold>Conclusion: </bold>Aberrant right subclavian artery with additional ultrasound findings constitute a strong predictor for aneuploidy. However, when ARSA is found in isolation, it confers no increased risk for aneuploidy or pathogenic CNVs. © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]