染色体微阵列技术在颈项透明层增厚产前诊断中的应用

Application of chromosome microarray in prenatal diagnosis of thickening of nuchal translucency

目的 本研究旨在探讨染色体微阵列技术(CMA)在颈项透明层增厚胎儿中的应用价值。方法 选取2018年6月至2020年6月在乌鲁木齐市妇幼保健院产前诊断中心进行产前诊断的样本,共纳入NT增厚(≥3.0 mm)且伴有/不伴有结构畸形的62例单胎妊娠样本。根据胎儿NT值大小分为4组:3.0~3.4 mm(33例)、3.5~4.4 mm(21例)、4.5~5.4 mm(3例)和≥5.5 mm(5例);根据NT增厚是否合并其他异常分为2组:单纯NT增厚(53例),NT增厚合并其他结构异常(9例)。通过染色体核型分析和CMA技术对胎儿可能的染色体异常进行分析。结果 染色体核型分析检出率为20.9%(13/62),包括21三体综合征8例,18三体综合征2例,特纳综合征2例,衍生染色体1例;CMA检出率为29.0%(18/62),包括12例非整倍体,1例致病性拷贝数变异和5例意义未明拷贝数变异。胎儿染色体非整倍体异常随NT厚度的增加呈大幅度上升趋势,在单纯NT增厚胎儿中,CNV占其总异常的27.8%(13/53),而在NT增厚合并其他结构异常胎儿中,CNV占其总异常的55.6%(5/9)。结论 CMA检测提高了染色体异常的检出率,在NT增厚但CMA检测阴性的胎儿中,不能排除不良结局的可能。

Objective This study aims to investigate the value of chromosomal microarray analysis(CMA)in fetuses with increased nuchal translucency.Methods Samples of prenatal diagnosis conducted at the prenatal diagnosis center of Urumqi Maternal and Child Health Hospital from June 2018 to June 2020 were selected.A total of 62 singleton pregnancy samples with NT thickening(≥3.0 mm)and with/without structural abnormalities were included.The pregnancies were divided into 4 groups based on the NT values:3.0~3.4 mm(33 cases),3.5~4.4 mm(21 cases),4.5~5.4 mm(3 cases),and≥5.5 mm(5 cases).Additionally,pregnan-cies were categorized into two groups based on whether there was increased NT with other abnormalities or not:simple increased NT(53 cases),and increased NT with other structural abnormalities(9 cases).All possible chromosomal anomalies were analyzed using karyotype analysis and CMA.Results The detection rate of chro-mosome karyotype analysis was 20.9%(13/62),which included 8 cases of trisomy 21 syndrome,2 cases of tri-somy 18 syndrome,2 cases of Turner syndrome and 1 case of derived chromosome.The detection rate of CMA was 29.0%(18/62),including 12 cases of aneuploidies,1 case of pathogenic CNV and 5 cases of VOUS.Fetal chromosomal aneuploidy abnormalities increased significantly with the increase in NT thickness,CNV ac-counted for 27.8%(13/53)of total abnormalities in fetuses with simple NT thickening,while in fetuses with NT thickening and other structural abnormalities,CNV accounted for 55.6%(5/9)of total abnormalities.Conclu-sion CMA detection improves the detection rate of chromosome abnormalities.In fetuses with NT thickening but negative CMA detection,the possibility of adverse outcomes cannot be ruled out.