超声异常胎儿的染色体核型分析及单核苷酸多态性芯片检测应用分析

目的:探讨染色体核型分析和单核苷酸多态性芯片(SNP-array)检测技术在超声异常胎儿产前诊断中的临床应用。方法:收集2017年1月1日-2018年12月31日于泉州市妇幼保健院·儿童医院产前诊断中心就诊的胎儿超声异常行羊水穿刺的孕妇278例,同时行染色体核型检查及SNP-array检测。结果:278例胎儿羊水染色体核型分析中276例(99.28%)培养成功,染色体核型分析阳性检出率8.33%(23/276)。SNP-array检测阳性检出率17.03%(47/276),2种检测方法阳性检出率比较差异有统计学意义(χ2=9.424,P=0.002)。染色体核型正常的253例孕妇中,SNParray阳性检出率为11.46%(29/253),其中致病性拷贝数变异(CNVs)检出率为2.76%(7/253),临床意义不明确的拷贝数变异(VOUS)检出率为8.70%(22/253)。NT增厚、骨骼肌肉及心血管系统异常胎儿的阳性CNVs检出率最高,其次为泌尿系统畸形和单项超声软指标异常胎儿。胎儿颜面部异常、消化系统畸形、呼吸系统畸形等,均未检出致病性CNVs。结论:SNP-array检测在异常结果检出率上存在一定的优势,而染色体核型分析可以弥补SNP-array检测在染色体平衡易位、倒位检查的不足。染色体核型分析联合SNP-array检测在超声异常胎儿中具有良好的应用价值和应用空间。

Chromosome Karyotype Analysis and SNP-Array Analysis of Abnormal Fetuses by Ultrasound

Objective:To investigate the role of chromosome karyotype analysis and single nucleotide polymorphism array(SNP-array)in prenatal diagnosis of abnormal fetuses.Methods:From January 1,2017 to December 31,2018,278 cases of pregnant women with fetal ultrasound abnormalities who received amniotic fluid puncture at our hospital were collected,and chromosome karyotype analysis and SNP-array were performed simultaneously.Results:The karyotype of amniotic fluid was analyzed in 278 cases,and the culture success rate was 99.28%in 276 cases.The positive detection rate of chromosome karyotype analysis was 8.33%(23/276).The positive detection rate of SNP-array was 17.03%(47/276).The difference of positive detection rate between the two test methods was statistically significant(χ2=9.424,P=0.002).In the cases with normal karyotype,the positive detection rate of SNP-array was 11.46%(29/253),among which the detection rate of pathogenic copy number variations(CNVs)was 2.76%(7/253),variants of unknown significance(VOUS)was 8.70%(22/253).The positive CNVs detection rate in abnormal fetus with NT thickening,bones,muscles and cardiovascular system is highest,followed by fetus with urinary tract malformation and abnormal single soft ultrasound index.No pathogenic CNVs were detected in fetal facial abnormalities,digestive system abnormalities,respiratory system abnormalities,etc.Conclusions:SNP-array technique has certain advantages in the detection rate of abnormal results,while chromosome karyotype analysis can make up for the deficiency of SNP-array in chromosome balance translocation and inversion.Chromosome karyotype analysis combined with SNP-array technique has good application value and space in ultrasonic abnormal fetus.