Chromosomal microarray in fetuses with increased nuchal translucency

• Published in: Ultrasound in obstetrics & gynecology 2015-01, Vol.45 (1), p.95-100
• Main Authors: Lund, I. C. B., Christensen, R., Petersen, O. B., Vogel, I., Vestergaard, E. M.
• Format: Article
• Language: English
• Subjects: array comparative genomic hybridization; chromosomal microarray; Chromosomes; Down syndrome; Down Syndrome - diagnosis; Down Syndrome - embryology; Down Syndrome - genetics; Female; Fetuses; genomic imbalance; Humans; nuchal translucency; Nuchal Translucency Measurement - methods; Polymerase Chain Reaction; Pregnancy; Pregnancy Trimester, First; Pregnancy, High-Risk; prenatal diagnosis; Prenatal Diagnosis - methods; Prospective Studies; Reproducibility of Results
• ISSN: 0960-7692; 1469-0705
• DOI: 10.1002/uog.14726

ABSTRACT Objective To assess the clinical value of using high‐resolution chromosomal microarray (CMA) for the examination of genomic imbalances in prenatal uncultured chorionic villus samples from fetuses with increased nuchal translucency (NT) and a normal quantitative fluorescent polymerase chain reaction (QF‐PCR) result, in a clinical setting in which more than 95% of pregnant women receive first‐trimester combined screening. Methods From January 2013 to July 2014, we included 132 chorionic villus samples from consecutive ongoing pregnancies, with fetal NT ≥ 3.5  mm at 11–13 weeks' gestation, from obstetric units (publicly funded healthcare) in Central and North Denmark Regions. DNA was extracted directly from the samples and examined with QF‐PCR (n = 132) and 180 kb oligonucleotide array‐based comparative genomic hybridization (n =  94). Results In 38 cases, aneuploidies for chromosomes 18, 21 or X, or triploidy, were detected by QF‐PCR. Among the 94 cases with a normal QF‐PCR result, we detected pathogenic copy number variants (CNVs) by CMA in 12 fetuses (12.8% (95% CI, 7.5–21.0%)). In an additional three (3.2%) cases, CNVs with uncertain clinical significance were detected. Conclusion CMA is a valuable diagnostic technique in pregnancies with isolated fetal NT ≥ 3.5 mm. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.