Du Erqiu, Feng Chun, Cao Yuming, Yao Yanru, Lu Jing, Zhang Yuanzhen
Department of Obstetrics and Gynecology,Zhongnan Hospital of Wuhan University,Wuhan,China.
Twin Res Hum Genet. 2017 Jun;20(3):242-249. doi: 10.1017/thg.2017.23. Epub 2017 May 9.
Massively parallel sequencing (MPS) technology has become increasingly available and has been widely used to screen for trisomies 21, 18, and 13 in singleton pregnancies. This study assessed the performance of MPS testing of cell-free fetal DNA (cffDNA) from maternal plasma for trisomies 21, 18, and 13 in twin pregnancies. Ninety-two women with twin pregnancies were recruited. The results were identified through karyotypes of amniocentesis or clinical examination and follow-up of the neonates. Fluorescent in-situ hybridization was used to examine the placentas postnatally in cases of false-positive results. The fetuses with autosomal trisomy 21 (n = 2) and trisomy 15 (n = 1) were successfully detected via MPS testing of cffDNA. There was one false-positive for trisomy 13 (n = 1), and fluorescence in-situ hybridization (FISH) identified confined placental mosaicism in this case. For twin pregnancies undergoing second-trimester screening for trisomy, MPS testing of cffDNA is feasible and can enhance the diagnostic spectrum of non-invasive prenatal testing, which could effectively reduce invasive prenatal diagnostic methods. In addition to screening for trisomy 21, 18, and 13 by cffDNA, MPS can detect fetal additional autosomal trisomy. False-positive results cannot completely exclude confined placental mosaicism.
大规模平行测序（MPS）技术已越来越普及，并已广泛用于单胎妊娠中21、18和13三体综合征的筛查。本研究评估了对双胎妊娠孕妇血浆中游离胎儿DNA（cffDNA）进行MPS检测用于21、18和13三体综合征筛查的性能。招募了92例双胎妊娠妇女。通过羊膜穿刺术的核型分析或临床检查及新生儿随访来确定结果。对于假阳性结果的病例，产后采用荧光原位杂交技术检查胎盘。通过对cffDNA进行MPS检测成功检测出2例21三体胎儿和1例15三体胎儿。有1例假阳性的13三体（n = 1），荧光原位杂交（FISH）在该病例中确定为局限性胎盘嵌合体。对于接受孕中期三体综合征筛查的双胎妊娠，对cffDNA进行MPS检测是可行的，并且可以扩大无创产前检测的诊断范围，从而有效减少侵入性产前诊断方法。除了通过cffDNA筛查21、18和13三体综合征外，MPS还可以检测胎儿额外的常染色体三体。假阳性结果不能完全排除局限性胎盘嵌合体。
