Microarrays In Prenatal Diagnosis

Objective Compared with traditional karyotype analysis,the value of chromosomal microarray analysis(CMA)in prenatal diagnosis was evaluated.To explore the problems of CMA technology in prenatal diagnosis,and to accumulate valuable clinical data for the application of CMA technology in prenatal diagnosis.Methods The antenatal diagnosis center of our hospital was selected from November 1,2017 to November 30,2017.258 pregnant women with amniocentesis prenatal indications and voluntary CMA and karyotype analysis were enrolled and signed an informed agreement.The amniotic fluid samples were collected and combined with clinical data to compare and compare the test results obtained by the two methods.Results In the 258 pregnant women,the traditional karyotype analysis was performed.The amniotic fluid culture failed in 2 cases,the success rate was99.2%,the CMA technique success rate was 100%,and the CMA results in the 2cases of amniotic fluid culture failure were normal.Traditional karyotype analysis diagnosed 32 cases of aneuploid chromosomal abnormalities,2 cases of sex chromosome abnormalities,2 cases of chromosome deletion,and 2 cases of chimera.In addition to detecting the same results,CMA can accurately identify the chromosomal content and source of unknown extra markers in the karyotype.The imbalance of chromosomes can give more accurate abnormal sites,and the chimeric results are more realistic.At the same time,CMA technique detected pathogenic gene copy number variation(CNVs)in 10 karyotype normal fetuses.The pathogenic CNVs in the CMA group was 18.75%(48/256),which was higher than the karyotype analysis group 14.84.%(38/256),the disease diagnosis rate increased by 3.91%.5.86%(15/256)of CNVs with unclear clinical significance were found in 15 normal babies with normal karyotype.Conclusion 1.Compared with karyotype analysis,the biggest advantage of CMA technology is that it has higher resolution,higherdiagnostic ability,no cell culture,short detection period,and the results are more realistic and helpful.More accurate genetic counseling and decisions about pregnancy outcomes.2.CMA found 10 cases of pathogenic CNVs in the fetus without abnormalities in karyotyping,which increased the diagnosis rate of disease by 3.91%.3.CMA technology cannot detect chromosomal balance rearrangement(translocation/inversion/insertion),so karyotyping is still necessary to further clarify the genomic complexity associated with apparently balanced rearrangement,whether or not to carry disease-causing genes.Pre-genetic diagnosis(PGD)provides relevant information.4.The interpretation of VOUS is still a problem in CMA application.Through parental verification,full genetic counseling,continuous improvement of technology and continuous enrichment of database,VOUS can be significantly reduced.