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: