染色体微阵列分析在高龄孕妇产前诊断胎儿染色体异常中的应用

Chromosomal microarray analysis in the prenatal diagnosis of fetal chromosomal aberration in gravidas with advanced age

目的探讨染色体微阵列分析(CMA)技术在单纯性高龄孕妇胎儿染色体异常的应用价值。方法收集单纯因高龄因素选择CMA检测的孕妇羊水标本2526例,回顾性分析不同年龄孕妇中胎儿染色体异常的发生率及类型。结果2526例孕妇羊水标本中,共检出染色体异常73例,检出率为2.89%,其中非整倍体32例,检出率为1.27%;致病性拷贝数变异(CNVs)30例,检出率为1.19%;可能致病CNVs11例,检出率为0.44%。有临床意义的CNVs检出率高于非整倍体的检出率。此外,检出临床意义不明CNVs(VUS)122例,占总数的4.83%(122/2526)。当预产年龄大于37岁时,每增长一岁染色体非整倍体检出率明显增高(P<0.05),但致病性CNVs检出率在各年龄段差异无统计学意义(P>0.05)。结论CMA不仅可以检测非整倍体异常,还可以检出微缺失/微重复等染色体拷贝数变异。当预产年龄大于37岁时,胎儿染色体非整倍体的发生率与年龄密切相关,但染色体拷贝数变异发生率与年龄无显著相关性。

Objective To evaluate the application of chromosomal microarray analysis(CMA)in the prenatal diagnosis of fetal chromosomal aberrations in gravidas with advanced maternal age(AMA).Methods A total of 2526 amniotic fluid samples were collected from pregnant women who chose CMA testing solely because of their advanced age.To retrospectively analyze the incidence and types of fetal chromosomal abnormalities in pregnant women of different ages.Results The overall detection rate of chromosomal aberration was 2.89%(73/2526).32 cases were aneuploidy,and the detection rate was 1.27%.30 cases of pathogenic CNVs,and the detection rate was 1.19%.11 possible pathogenic CNVs,and the detection rate was 0.44%.The detection rate of clinically significant CNVs was higher than that of aneuploidy.Besides,the detection rate of CNVs of unknown clinical significance(VUS)was 4.83%(122/3677).When the pregnant woman is older than 37,the detection rate of aneuploidies increased significantly with increased maternal age(P<0.05).However,there were no significant differences in the detection rate of clinically significant CNVs among different maternal age groups(P>0.05).Conclusion Our findings suggest that,compared with traditional karyotype analysis,CMA not only detects aneuploidies,but also detect pathogenic CNVs,including microdeletion/microduplication.The detection rate of fetal aneuploidies was closely correlated to maternal age.However,no correlation was found between the detection rate of clinically significant CNVs and maternal age.