BACs-on-Beads技术联合染色体核型分析在高龄孕妇产前诊断中的应用

Application of BACs-on-Beads assay combined with chromosomal karyotyping in prenatal diagnosis of elderly pregnant women

目的探讨染色体核型分析和BACs-on-Beads(BoBs)技术在高龄孕妇产前诊断中的临床应用价值。方法选取2017年1月至2021年4月在新长安妇产医院进行产前诊断的1033例高龄孕妇羊水细胞行染色体核型分析和BoBs检测,结果进行分析比较。若遇微缺失/微重复病例,染色体微阵列技术(CMA)提供进一步验证。结果1033例高龄孕妇中,共检出染色体异常103例,异常检出率为9.97%,其中染色体核型分析检出101例,BoBs检出100例,高龄合并无创产前检测高风险的检出率最高,为70.41%。103例异常核型中,21三体73例,18三体12例,13三体1例,47,XXX 4例,47,XYY 3例,45,X 1例,47,XXY 3例,性染色体嵌合1例,BoBs检测结果与染色体核型分析结果一致;BoBs检出22q11.2微重复综合征1例,Smith-Magenis综合征1例,与CMA检测结果一致,染色体核型分析未检出;染色体核型分析检出结构异常3例,BoBs未检出。结论“染色体核型分析+BoBs”的产前诊断模式可广泛应用于高龄孕妇,在提高检测效率的同时减少染色体异常胎儿的出生风险。

Objective To evaluate the value of BoBs assay and conventional chromosomal karyotyping in prenatal diagnosis of elderly pregnant women.Methods A total of 1033 cases of elderly pregnant women who received prenatal diagnosis in New Changan International Maternity Hospital from January 2017 to April 2021 were analyzed by BoBs and chromosomal karyotyping simultaneously,and the results were compared.Chromosomal microarray analysis(CMA)provided further validation for the cases of microdeletion and microduplication.Results 103 chromosomal abnormalities were detected in 1033 samples,and the overall detection rate was 9.97%.101 cases were detected by chromosomal karyotyping and 100 cases were detected by BoBs.Advanced maternal age combined with increased noninvasive prenatal testing risk accounted for the highest abnormality,at 70.41%.Among the 103 chromosomal abnormalities,73 trisomy 21,12 trisomy 18,1 trisomy 13,447,XXX,347,XYY,145,X,347,XXY,and 1 sex chromosomal mosaicism were detected by both chromosomal karyotyping and BoBs assay.122q11.2 microduplication and 1 Smith-Magenis syndrome were successfully detected by BoBs and missed by karyotyping.3 structural abnormalities were detected by chromosomal karyotyping,but missed by BoBs.Conclusion BoBs and chromosomal karyotyping can be applied to prenatal diagnosis of elderly pregnant women,which can improve detection efficiency and reduce the occurrence of birth defects.