扩展性无创产前检测双胎之一22q11.2缺失综合征假阴性结果的原因分析  

Analysis of a twin pregnancy with false negative result for 22q11.2 deletion syndrome by expanded non-invasive prenatal testing

作　　者：赵干业 焦智慧[1] 代鹏[1] 赵晓燕[1] 孔祥东[1] Zhao Ganye;Jiao Zhihui;Dai Peng;Zhao Xiaoyan;Kong Xiangdong(Genetics and Prenatal Diagnosis Center,Department of Obstetrics and Gynecology,the First Affiliated Hospital of Zhengzhou University,Zhengzhou,Henan 450052,China)

机构地区：[1]郑州大学第一附属医院妇产医学部遗传与产前诊断中心,郑州450052

出　　处：《中华医学遗传学杂志》2023年第12期1451-1454,共4页Chinese Journal of Medical Genetics

基　　金：郑州大学第一附属医院青年创新基金;河南省科技攻关计划(202102310391)

摘　　要：目的探讨1例扩展性无创产前检测(NIPT-plus)双胎之一22q11.2缺失综合征(22q11.2 DS)假阴性的原因。方法对1例NIPT-plus结果为阴性,后期因超声异常行羊水穿刺的辅助生殖双胎样本,获取胎儿细胞后行核型分析和拷贝数变异测序(CNV-seq)检测。收集并分析孕妇的临床信息及检测数据,探讨假阴性的原因。结果NIPT-plus的uniMap reads为11.77 Mb,胎儿游离DNA浓度为3.05%。羊水核型结果显示一胎为46,XY,另一胎儿为46,XX,均正常。CNV-Seq结果显示一胎正常,另一胎为缺失大小为2.58 Mb的22q11.2 DS。结论上述假阴性应是由较低的胎儿游离DNA浓度、孕妇较高的BMI、辅助生殖、双胎以及较小的缺失片断等综合因素共同引起。对于NIPT-plus低风险者的后续超声检查不可忽视。Objective To explore the cause for a twin pregnancy with false negative result for 22q11.2 deletion syndrome by expanded non-invasive prenatal testing(NIPT-plus).Methods A pregnant woman with twin pregnancy through in-vitro fertilization and negative result of NIPT-plus was selected as the study subject.Amniocentesis was conducted after ultrasonic finding of fetal abnormalities.In addition to conventional G-banded karyotyping,copy number variation sequencing(CNV-Seq)was used to detect chromosomal microdeletion and microduplication.Clinical data of the woman were analyzed to explore the reasons underlying the false negative result.Results NIPT-plus has yielded a negative result with 11.77 Mb unique reads and 3.05%fetal fraction.Both fetuses had a normal karyotype(46,XY and 46,XX).CNV-seq indicated that one of the fetuses was normal,whilst the other was diagnosed with a 2.58 Mb deletion in the 22q11.2 region.Conclusion The false negative result may be attributed to the combined influence of low fetal fraction,high BMI,twin pregnancy through IVF and a relatively small deletion fragment.Ultrasonography exam following a low-risk result of NIPT-plus should not be neglected.

关 键 词：扩展性无创产前检测 22q11.2缺失综合征 假阴性 超声 

分 类 号：R714.5[医药卫生—妇产科学]