INTRODUCTION:
In recent years, copy number variation sequencing (CNV-seq) has been gradually applied in prenatal diagnosis. Is this technique used alone or in combination with karyotyping in prenatal diagnosis? This issue is confusing for clinicians.
Aneuploidy, large deletions/duplications and pathogenic copy number variations(pCNVs) are the major causes of birth defects[1] . Karyotyping has been the ”gold standard” of chromosome test. It can identify the majority of chromosome abnormalities, which included polyploidy, aneuploidy, greater than 10 Mb deletion/duplication, balanced structure rearrangement (reciprocal translocation, Robertsonian translocation, inversion, etc.). However, it has long detection period, low success rate, low resolution (chromosome abnormality less than 5 Mb even 10 Mb cannot be identified)[2] . Chromosomal microarray analysis (CMA) can provide higher resolution. This can detect genome-wide imbalance chromosomal changes and pinpoint the location of abnormal changes. However, the cost of CMA was higher. The chromosomal regions that were not covered by probes cannot be detected[3] .Therefore, there is an urgent need for a more economical method to detect chromosomal disorders comprehensively and accurately. Copy number variation sequencing (CNV-seq) based on next generation sequencing(NGS) technology provides a new method for prenatal diagnosis. Compared with karyotyping, it has the advantages of wide detection range, high resolution, high success rate, easy operation and short detection period. This study retrospectively analyzed amniocentesis samples that were analyzed by both CNV-seq and karyotyping, aiming to explore the value of CNV-seq in prenatal diagnosis.
Objects and Methods: