Whole exome sequencing(WES) and CNV analysis
The genomic DNA of amniotic fluid was broken into random fragments and purified, and whole genome exome capture was performed for sequencing library preparation. The Illumina Hiseq XTen sequencer was used to perform double‐ended high‐throughput sequencing with a length of 150 bp. The raw data obtained by the sequencing were quality‐controlled, and the basic data were analyzed and filtered to remove the linker sequence and repeat sequence. Data were analyzed using the Anno variant site detection system, the XYGeneRanger variant site annotation interpretation system.