染色体微阵列对颈项透明层增厚胎儿的产前诊断价值

Prenatal diagnosis value of chromosomal microarray in fetuses with thickened nuchal translucency

目的:探讨采用染色体微阵列(CMA)技术分析胎儿颈项透明层(NT)增厚的产前诊断价值。方法:选取胎儿NT增厚(NT≥2.5 mm)的孕11~14周孕妇139例。以NT值为1 mm为间隔,将胎儿分为4组,包括2.5~3.4 mm、3.5~4.4 mm、4.5~5.4 mm和≥5.5 mm组。对胎儿标本进行核型分析和拷贝数变异(CNV)测序。结果:随着NT厚度的增加,活产率呈下降趋势(P<0.01),相应异常CNV检出率呈上升趋势(P<0.01);139例中染色体核型异常35例(25.2%),CNV异常45例(32.3%);12例CNV异常且染色体核型正常的病例中,致病性CNV 2例,临床意义不明CNV 7例,可能为良性CNV 3例;高龄孕妇CNV异常率与非高龄孕妇CNV比较差异无统计学意义(P>0.05),单独NT异常CNV异常率低于NT合并其他超声指标异常(P<0.05),活产者CNV异常率低于引产者(P<0.01)。结论:NT增厚胎儿应同时进行CMA联合核型分析,为遗传咨询提供依据,对产前诊断具有重要意义。

Objective:To explore the prenatal diagnostic value of chromdsome microarray(CMA)in analyzing the thickening of nuchal translucency(NT)of fetus.Methods:A total of 139 women with gestational 11-14 weeks whose fetuses were detected with increased NT(NT≥2.5 mm)were selected.They were divided into four groups with NT value of 1 mm as an interval,including 2.5-3.4 mm,3.5-4.4 mm,4.5-5.4 mm,and≥5.5 mm groups.Fetal specimens were performed for karyotype analysis and copy number variants(CNV)sequencing.Results:With the increase in NT thickness,the live birth rate tended to decrease(P<0.01)and the corresponding abnormal CNV detection rate tended to increase(P<0.01).Among the 139 cases,35 cases(25.2%)had abnormal karyotype,45 cases(32.3%)had abnormal CNV.Among the 12 cases with abnormal CNV and normal karyotype,2 cases were pathogenic CNV,7 cases were CNV of unknown clinical significance,and 3 cases were possibly benign CNV.There was no statistically significant difference in CNV abnormalities between elderly and non-elderly pregnant women(P>0.05).The rate of abnormal CNV in NT alone was lower than that of NT combined with other ultrasound(P<0.05),and the rate of abnormal CNV was lower than that of induced labor in those with live births(P<0.01).Conclusions:NT thickened fetuses should be combined with CMA karyotype analysis to provide the basis for genetic counseling,which is of great significance for prenatal diagnosis.