Abstract:

Objective To explore the application value of noninvasive prenatal testing（NIPT）in the detection of copy number variation on chromosomes except chromosome 21，18，13 and sex chromosomes. Methods A total of 114 patients with CNV except chromosome 21，18，13 and sex chromosome abnormalities were selected from January 2019 to January 2021. Amniocentesis was performed under the informed consent principle. Chromo⁃ some karyotype analysis and chromosome microarray analysis（CMA）were performed at the same time and patients′ conditions were followed up. Results Among 114 pregnant women with chromosomal copy number variation detected by NIPT，a total of 37 cases of CNVs，representing a percentage of 32.46%（37/114），were detected which were consistent with the results of NIPT，among which 12 cases of CNVs，representing a percentage of 32.43%（12/ 37），had unclear clinical significance. Follow⁃up data showed that 22 pregnancies were terminated，and 90 births were normal while 2 pregnancies were normal. Conclusion NIPT suggested microdeletion and microduplication of fetal chromosomes，so prenatal diagnosis combined with chromosomal karyotype analysis and CMA was recommended to confirm the diagnosis. Parental comparison was performed according to the results if necessary，so as to provide advice and basis for clinical genetic counseling.

Key words:

noninvasive prenatal testing, chromosome karyotype analysis, chromosome microarray analysis, copy number variation