颈项透明层厚度增厚胎儿应用染色体微阵列技术效果分析及其临床意义

The application effect of chromosome microarray analysis and its clinical significance in fetuses with thickened nuchal translucency

目的探讨染色体微阵列技术(CMA)在颈项透明层(NT)厚度增厚胎儿中的应用效果及其临床意义。方法选取2018年9月至2020年8月广东省惠州市第二妇幼保健院妊娠早期NT筛查异常(≥2.5 mm)胎儿203例,行传统染色体核型分析及CMA检测,分析两种检测方法胎儿染色体数目异常数发生情况。根据NT值分为四组,2.5~2.9 mm组、3.0~3.9 mm组、4.0~4.9 mm组及≥5.0 mm组,比较不同NT值组间胎儿染色体异常的发生率。结果传统核型分析检出染色体异常70例(34.98%),CMA额外检出7例致病性拷贝数变异(CNVs),共77例(37.93%);随着NT值的增加,胎儿染色体异常发生率也随之增加(P<0.05);7例染色体核型正常的胎儿经CMA检出的CNVs具有致病性,与传统染色体核型分析检测结果比较,CMA检测的检出率提高了3.45%(7/203)。结论随胎儿NT值升高发生染色体异常风险随之增大,CMA能检测传统核型分析无法检出的染色体拷贝数变异,临床上采用CMA检测在NT增厚胎儿的遗传学分析有重要的应用价值。

Objective To investigate the application effect of chromosome microarray analysis(CMA)in fetuses with thickened nuchal translucency(NT)and its clinical significance.Methods A total of 203 fetuses with abnormal NT screening(≥2.5 mm)in early pregnancy in Huizhou Second Maternal and Child Healthcare Hospital from September 2018 to August 2020 were selected for traditional karyotype analysis and CMA testing.The occurrence of abnormal number of fetal chromosomes in both testing methods was analyzed.These fetuses were divided into 4 groups based on the NT values:2.5-2.9 mm group,3.0-3.9 mm group,4.0-4.9 mm group and≥5.0 mm group.The incidence of fetal chromosomal abnormalities was compared among groups with different NT values.Results 70 fetuses(34.98%)with chromosomal abnormalities were detected by traditional karyotype analysis,and 7 additional fetuses with pathogenic copy number variants(CNVs)were detected by CMA,a total of 77 fetuses(37.93%).The incidence of fetal chromosomal abnormalities increased with increasing NT values(P<0.05).The CNVs detected by CMA in 7 fetuses with normal karyotype were pathogenic.The detection rate of CNVs detected by CMA was increased by 3.45%(7/203)compared with the results of traditional karyotype analysis.Conclusion The risk of chromosomal abnormalities increases with increasing fetal NT values,and CMA can detect chromosomal CNVs that cannot be detected by traditional karyotype analysis.Therefore,it is clinically important to use CMA for genetic analysis of fetuses with thickened NT.