Value of chromosome microarray analysis combined with chromosome karyotype analysis in prenatal diagnosis for diagno-sing Downs syndrome
Objective:To explore the application value of chromosome microarray analysis(CMA)combined with chro-mosome karyotype analysis for diagnosing Down's syndrome.Methods:The clinical data of 122 high-risk pregnant women who had undergone amniotic fluid puncture from December 2022 to December 2023 were collected retrospec-tively.The results of the fetal chromosome karyotype analysis was as the gold standard,the diagnostic accuracy rate of the fetal Down's syndrome was compared among the free DNA detection technology,CMA and CMA combined with the free DNA detection technology.Receiver operator characteristic(ROC)curve was drawn to analyze the efficacy of the chromosome karyotype analysis,CMA and CMA combined with karyotype analysis for diagnosing Down's syn-drome.The results of the karyotype analysis and CMA were compared among the women with different high-risk pre-natal diagnostic indications.The karyotype detection results of the women with fetal chromosome abnormalities were observed.Results:In 122 high-risk pregnant women who had been given routine amniotic fluid puncture for antenatal examination,there were 14 cases with the detected fetal Down's syndrome,with the detection rate of 11.5%.The ac-curacy,the area under the curve(AUC),the sensitivity and the specificity of the karyotype analysis for diagnosing fe-tal Down's syndrome were 92.6%(113/122),0.808,64.3%and 96.3%,respectively.The accuracy,the area under the curve(AUC),the sensitivity and the specificity of CMA for diagnosing fetal Down's syndrome were 94.3%(115/122),0.843,71.4%and 97.2%,respectively.The diagnostic accuracy and AUC of the combination of the karyotype analysis and CM A for diagnosing fetal Down's syndrome were significantly higher than those of the karyotype analysis or CMA alone(P<0.05).The numbers of fetal Down's syndrome diagnosed by the karyotype analysis alone,CMA a-lone,and the combined detection of the karyotype analysis and CMA for the women with ultrasound fetal neck thicken-ing of the transparent layer(NT)were 2 cases,1 case and 2 cases,respectively.The numbers of fetal Down's syn-drome diagnosed by the karyotype analysis alone,CMA alone,and the combined detection of the karyotype analysis and CMA for the women aged>35 years old were 0 case,1 case and 2 cases,respectively.The numbers of fetal Down's syndrome diagnosed by the karyotype analysis alone,CMA alone,and the combined detection of the karyotype analysis and CMA for the women with abnormal noninvasive prenatal testing(NIPT)were 5 cases,5 cases and 6 ca-ses,respectively.The numbers of fetal Down's syndrome diagnosed by the karyotype analysis,CMA and the com-bined detection of the karyotype analysis and CMA for the women with high-risk fetal Down's syndrome were 2 cases,2 cases and 3 cases,respectively.The women with the fetal karyotype abnormalities included 7 cases with the chromo-some numerical abnormalities and 2 cases with the chromosome structural abnormalities.Conclusion:The combined CMA and karyotype analysis for diagnosing the fetal Down's syndrome has the highest accuracy and sensitivity,and which has important reference value for diagnosing fetal Down's syndrome in clinical antenatal diagnosis.