The detection kit, which is based on the BES 4000 platform, is used to perform low-depth whole-genome sequencing of DNA. The sequencing results are compared to the base sequence of the human reference genome, and CNVs in the tested samples are discovered using bioinformatics analysis. It is often used to find out why a woman keeps having miscarriages, find out what is wrong with an abnormal fetus, and help with a prenatal diagnosis.