无创产前检测在筛查胎儿染色体拷贝数变异中的应用价值分析

The application value analysis of non-invasive prenatal testing in fetal chromosomal copy number variation

摘要

目的 探讨无创产前检测(NIPT)技术在产前筛查胎儿染色体拷贝数变异(CNVs)中的临床意义及应用价值。方法 选择2018年1月至2021年7月在淮安市妇幼保健院进行NIPT检测,结果提示可能为胎儿CNVs的224例孕妇为研究对象;对其中171例孕妇进行了羊水穿刺及进一步的产前诊断[羊水染色体核型分析及染色体微阵列分析(CMA)],获得胎儿羊水样本171例.对比分析羊水染色体核型及CMA结果与NIPT结果,并进行随访。结果 根据CNVs不同类型分组,微缺失组占所有CNVs的54.02%(121/224),微重复组占所有CNVs的39.73%(89/224),微缺失合并微重复组占所有CNVs的6.25%(14/224);微缺失组、微重复组、微缺失合并微重复组羊水穿刺阳性预测值分别为56.67%、50.70%、80.00%,三组间阳性预测值比较差异无统计学意义(χ²=3.412,P>0.05).根据CNVs不同片段分组,>10Mb组占所有CNVs的18.75%(42/224),5~10Mb组占所有CNVs的20.54%(46/224),<5Mb组占所有CNVs的60.71%(136/224);>10Mb组、5~10Mb组、<5Mb组羊水穿刺阳性预测值分别为56.76%、60.00%、53.54%,三组间阳性预测值比较差异无统计学意义(χ²=0.465,P>0.05).在经过羊水穿刺进行染色体核型分析和CMA确诊的95例胎儿CNVs中,致病性CNVs占33.68%(32/95),可能致病性CNVs占21.05%(20/95),意义不明确CNVs占41.05%(39/95),可能良性CNVs占4.21%(4/95),无良性CNVs病例.对NIPT提示可能为胎儿CNVs的224例孕妇进行电话或者门诊随访,随访率为86.16%(193/224);但接受羊水穿刺的孕妇随访率为100.00%.在致病性CNVs中选择继续妊娠的孕妇共5例,有3例经对父母进行CMA验证发现CNVs来自母源,有2例拒绝验证,5例新生儿中均未见明显异常表型.在可能致病性CNVs中选择继续妊娠的孕妇共10例,有3例经对父母进行CMA验证发现CNVs分别来自父源、母源、新发突变,有7例拒绝验证。结论 应用NIPT对胎儿CNVs进行初步筛查有效且可行,对于NIPT提示可能为胎儿CNVs的孕妇,必须建议其进行规范的超声筛查及侵入性产前诊断.

Abstract

Objective To explore the clinical significance and application value of non-invasive prenatal testing (NIPT) technology in prenatal screening for fetal chromosomal copy number variations (CNVs). Methods 224 pregnant women who underwent NIPT testing at Huai'an Maternal and Child Health Hospital from January 2018 to July 2021, with results suggesting possible fetal CNVs, were selected as the study subjects. Amniocentesis and further prenatal diagnosis [amniotic fluid karyotyping and chromosome microarray analysis (CMA)] were performed in 171 of these pregnancies, and 171 fetal amniotic fluid samples were obtained. The results of amniotic fluid karyotyping and CMA were compared and analyzed with the results of NIPT and followed up. Results According to the grouping of different types of CNVs, the microdeletion group accounted for 54.02% (121/224) of all CNVs, the microduplication group accounted for 39.73% (89/224) of all CNVs, and the microdeletion-combined-microduplication group accounted for 6.25% (14/224) of all CNVs, the positive predictive values of amniocentesis in the microdeletion group, the microduplication group, and the microdeletion-combined-microduplication group were 56.67%, 50.70% and 80.00%, respectively, and the difference in positive predictive value among the three groups was not statistically significant (χ²=3.412, P>0.05). According to the grouping of different segments of CNVs, >10Mb group accounted for 18.75% (42/224) of all CNVs, 5-10Mb group accounted for 20.54% (46/224) of all CNVs, <5Mb group accounted for 60.71% (136/224) of all CNVs, the positive predictive value of amniocentesis in >10Mb group, 5-10Mb group, <5Mb group were 56.76%, 60.00% and 53.54%, respectively, and the difference in positive predictive value among the three groups was not statistically significant (χ²=0.465, P>0.05). Among the 95 fetal CNVs diagnosed after amniocentesis for chromosomal karyotyping and CMA, pathogenic CNVs accounted for 33.68% (32/95), probable pathogenic CNVs accounted for 21.05% (20/95), CNVs of uncertain significance accounted for 41.05% (39/95), probable benign CNVs accounted for 4.21% (4/95), and there were no benign CNVs cases. 224 pregnant women whose NIPT suggested fetal CNVs were followed up by telephone or outpatient, the follow-up rate was 86.16% (193/224). However, the follow-up rate of pregnant women who underwent amniocentesis was 100.00%. A total of 5 pregnant women who chose to continue their pregnancy among pathogenic CNVs were found to have CNVs of maternal origin in 3 cases verified by CMA of the parents, 2 cases refused to be verified, and none of the 5 neonates showed any obvious abnormal phenotype. There were 10 cases of pregnant women who chose to continue pregnancy among the potentially pathogenic CNVs, 3 cases were found to have CNVs of paternal origin, maternal origin, and new mutations, respectively, by CMA of the parents, and 7 cases refused to be verified. Conclusion The application of NIPT for the preliminary screening of fetal CNVs is effective and feasible, and standardized ultrasound screening and invasive prenatal diagnosis must be recommended for pregnant women with possible CNVs indicated by NIPT.

关键词

无创产前检测 / 染色体拷贝数变异 / 染色体微阵列分析 / 阳性预测值 / 产前诊断

Key words

non-invasive prenatal testing / chromosomal copy number variations / chromosomal microarray analysis / positive predictive value / prenatal diagnosis

参考文献

[1] 刘学军, 刘慈, 马良, 等. 无创产前筛查检测胎儿染色体缺失或重复的应用价值分析[J]. 中国优生与遗传杂志, 2019, 27(7): 811-813, 860.

[2] 黄晓莉, 孙丽洲. 无创产前检测在胎儿性染色体疾病筛查中应用的临床研究[J]. 南京医科大学学报(自然科学版), 2022, 42(7): 1018-1024, 1035.

[3] Manning M, Hudgins L. Addendum:array-based technology and recommendations for utilization in medical genetics practice for detection of chromosomal abnormalities[J]. Genet Med, 2020, 22(12): 2126.

[4] Yu H E, Hawash K, Picker J, et al. A recurrent 1.71Mb genomic imbalance at 2q13 increases the risk of developmental delay and dysmorphism[J]. Clin Genet, 2012, 81(3): 257-264.

[5] 黎冬梅, 张红云, 唐新华, 等. 无创产前检测胎儿染色体拷贝数变异的临床价值初探[J]. 中国实用妇科和产科杂志, 2019, 35(5): 554-559.

[6] Yang J, Wu J, Peng H, et al. Performances of NIPT for copy number variations at different sequencing depths using the semiconductor sequencing platform[J]. Hum Genomics, 2021, 15(1): 41.

[7] Chen Y, Lu L, Zhang Y, et al. Clinical application of expanded noninvasive prenatal testing for fetal chromosome abnormalities in a cohort of 39580 pregnancies[J]. Am J Med Genet A, 2022, 188(5): 1426-1434.

[8] Chen Y, Yu Q, Mao X, et al. Noninvasive prenatal testing for chromosome aneuploidies and subchromosomal microdeletions/microduplications in a cohort of 42910 single pregnancies with different clinical features[J]. Hum Genomics, 2019, 13(1): 60.

[9] Hu H, Wang L, Wu J, et al. Noninvasive prenatal testing for chromosome aneuploidies and subchromosomal microdeletions/microduplications in a cohort of 8141 single pregnancies[J]. Hum Genomics, 2019, 13(1): 14.

[10] Wang C, Tang J, Tong K, et al. Expanding the application of non-invasive prenatal testing in the detection of foetal chromosomal copy number variations[J]. BMC Med Genomics, 2021, 14(1): 292.

[11] 丁昭宁, 白文学, 刘文兰, 等. NIPT-plus在无创产前检测CNV中的临床价值分析[J]. 江西医药, 2020, 55(10): 1359-1362.

[12] Riley K N, Catalano L M, Bernat J A, et al. Recurrent deletions and duplications of chromosome 2q11.2 and 2q13 are associated with variable outcomes[J]. Am J Med Genet A, 2015, 167A(11): 2664-2673.

[13] 文思敏, 隗伏冰, 何怡, 等. 基于大规模平行测序的无创检测技术在胎儿染色体缺失或重复检测中的应用[J]. 中华医学遗传学杂志, 2014, 31(5): 557-560.

[14] 张颖, 温艳, 温树国, 等. NIPT对不同孕妇群体的染色体疾病及CNVs的诊断价值的研究[J]. 中国优生与遗传杂志, 2020, 28(6): 691-694.

[15] 黄晓莉, 孙丽洲. 218例侧脑室增宽胎儿的染色体检测结果和妊娠结局分析[J]. 南京医科大学学报(自然科学版), 2021, 41(4): 593-599, 633.

[16] Yu D, Zhang K, Han M, et al. Noninvasive prenatal testing for fetal subchromosomal copy number variations and chromosomal aneuploidy by low-pass whole-genome sequencing[J]. Mol Genet Genomic Med, 2019, 7(6): e674.

[17] Suzumori N, Sekizawa A, Takeda E, et al. Retrospective details of false-positive and false-negative results in non-invasive prenatal testing for fetal trisomies 21,18 and 13[J]. Eur J Obstet Gynecol Reprod Biol, 2021, 256: 75-81.

[18] Fleddermann L, Hashmi S S, Stevens B, et al. Current genetic counseling practice in the United States following positive non-invasive prenatal testing for sex chromosome abnormalities[J]. J Genet Couns, 2019, 28(4): 802-811.

[19] Feng W, Liu G, Qin J. Ginkgo biloba Damo injection combined with troxerutin regulates the TLR4/NF-κB pathway and promotes the recovery of patients with acute cerebral infarction[J]. Am J Transl Res, 2021, 13(4): 3344-3350.

[20] 邹卉, 李育霖, 田丽萍. 中链酰基辅酶A脱氢酶缺乏症诊治进展[J]. 中国实用儿科杂志, 2019, 34(1): 22-25.

[21] 叶小青. 无创产前检测技术对胎儿染色体拷贝数变异的研究[D]. 广州: 广州医科大学, 2020.