Yang Jiexia, Qi Yiming, Guo Fangfang, Hou Yaping, Peng Haishan, Wang Dongmei, Oy Haoxin, Yin Aihua
Prenatal Diagnosis Centre, Guangdong Women and Children Hospital, Guangzhou, Guangdong 511400 China.
Maternal and Children Metabolic-Genetic Key Laboratory, Guangdong Women and Children Hospital, Guangzhou, Guangdong 511400 China.
Mol Cytogenet. 2017 Oct 27;10:40. doi: 10.1186/s13039-017-0341-5. eCollection 2017.
The non-invasive prenatal testing that evaluates circulating cell free DNA, and has been established as an additional pregnancy test for detecting the common fetal trisomies 21, 18 and 13 is rapidly revolutionizing prenatal screening as a result of its increased sensitivity and specificity. However, false positive and false negative results still exist.
We presented a case in which the non-invasive prenatal testing results were normal at 15 gestational age (GA), but an ultrasound examination at 30GA showed that the fetus had heart abnormalities, and the third trimester ultrasound at 33GA noted multiple anomalies including a 3.0 mm ventricular septal defect. Along with cordocentesis at 33GA, the cord blood sample cytogenetics analysis showed a mos 47,XN,+18[61]/46,XN[39] T18 karyotype. Six placental biopsies confirmed that the chromosome 18 placenta chimerism ratio had changed from 33% to 72%. Ultimately, the pregnancy was interrupted at 34GA.
We presented this case to highlight the need to clearly explain false positive or false negative results to patients. We believe that this information will also influence the development of future diagnostic test methodologies.
评估循环游离DNA的无创产前检测已被确立为检测常见胎儿21三体、18三体和13三体的一项额外的妊娠检测方法，由于其敏感性和特异性的提高，正在迅速革新产前筛查。然而，假阳性和假阴性结果仍然存在。
我们报告了一例病例，该病例在孕15周时无创产前检测结果正常，但孕30周时超声检查显示胎儿有心脏异常，孕33周时孕晚期超声检查发现包括3.0毫米室间隔缺损在内的多种异常。在孕33周时进行脐带穿刺，脐带血样本细胞遗传学分析显示核型为mos 47,XN,+18[61]/46,XN[39] T18。六次胎盘活检证实18号染色体胎盘嵌合率从33%变为72%。最终，在孕34周时终止妊娠。
我们报告此病例以强调向患者清楚解释假阳性或假阴性结果的必要性。我们认为该信息也将影响未来诊断检测方法的发展。
