目的 探讨无创产前基因检测阳性病例的临床规范化处理。方法 收集2016年1月至2017年8月在徐州市中心医院进行无创产前诊断的24例阳性病例孕妇为研究对象，进一步行羊水或脐血穿刺以确诊，所有病例均进行电话随访。结果 无创DNA产前检测异常者24例：9例提示胎儿21-三体高风险，4例提示18-三体高风险，1例提示7号染色体三体可能，1例7号染色体重复51Mb，1例提示15-三体高风险，1例提示16号染色体异常?，6例性染色体异常（2例提示45,XO，2例提示47,XYY，1例提示47,XXX，1例胎儿性别待查），1例18染色单体或部分缺失，同时怀疑性染色体及多条染色体异常。24例中1例放弃产前诊断直接引产，18例行羊水穿刺，5例行脐静脉穿刺。确诊胎儿染色体异常疾病者12例，其中8例21-三体，2例18-三体，2例47,XYY，余11例无创DNA异常孕妇羊水/脐血穿刺结果正常，10例引产，13例（包括2例47,XYY）继续妊娠，跟踪随访13例新生儿结局良好。无创产前检测对21和18-三体的符合率达88.89%和50%。对于性染色体异常的筛查，47,XYY的符合率为100%，但对45,X和47,XXX的符合率为0。结论 无创产前基因测序技术对染色体的非整倍体检测有较高的敏感性和特异性，对21-三体和18-三体检出率较高，但仍存在一定的假阳性，无创DNA测序发现异常的孕妇，仍需进行介入性产前诊断确诊，避免无辜胎儿受到伤害。
Objective To explore the clinical standard management of positive cases tested by noninvasive prenatal gene detection. Methods 24 pregnant women with noninvasive prenatal diagnosis in Xuzhou Central Hospital from January 2016 to August 2017 were collected as research objects, and then amniotic fluid or umbilical cord blood puncture was further performed to confirm the previous diagnosis. Pregnancy outcomes of all cases were followed up by telephone. Results 24 cases of noninvasive DNA were abnormal: 9 cases suggesting the high risk of trisomy 21, 4 cases presenting the high risk of trisomy 18, 1 case suggesting the possibility of trisomy 7, 1 case with a repetition of 51Mb of chromosome 7, 1 case showing the high risk of trisomy 15, and 1 case indicating a possible abnormality of chromosome 16, 6 cases of sex chromosome abnormality (the karyotypes were 45,XO of 2 cases, 47,XYY of 2 cases, 47,XXX of 1 case, and fetal sex to be checked of 1 case), 1 case referring to 18 chromatid or partial deletion, and simultaneously suspecting sex chromosome abnormality and multiple chromosome abnormality. Among the 24 pregnant women, 1 case gave up the interventional prenatal diagnosis and took the induction of labour directly, 18 patients accepted amniotic fluid puncture while 5 underwent accepted umbilical vein puncture. 12 cases of fetal chromosomal abnormalities were definitely diagnosed, including 8 cases of 21-trisomy, 2 cases of 18-trisomy, 2 cases of 47 XYY, and the remaining 11 cases of non-invasive DNA abnormalities showed normal results of amniotic fluid/umbilical cord blood puncture. 10 cases took the induction of labour, 13 cases (including 2 cases of 47 XYY) continued pregnancy, and 13 cases of neonatal follow-up showed good results. Noninvasive prenatal testing for 21 and 18- trisomy had a coincidence rate of 88.89% and 50%. For the screening of sex chromosome abnormality, the coincidence rate of 47, XYY is 100%, however, the coincidence rate of 45,X and 47 and XXX is 0. Conclusions Noninvasive prenatal gene detection has a high sensitivity and specificity for chromosome aneuploidy detection, and the detection rate of 21-trisomy and 18-trisomy is high, while there is still some false positive, when noninvasive DNA sequencing found abnormal pregnant women, we still need to carry out interventional prenatal diagnosis to avoid innocent fetal injury.
