Bonanni Giulia, Trevisan Valentina, Zollino Marcella, De Santis Marco, Romanzi Federica, Lanzone Antonio, Bevilacqua Elisa
Unit of Obstetrics and Gynecology, Università Cattolica del Sacro Cuore, Rome, Italy.
Unit of Medical Genetics, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy.
Front Genet. 2022 May 12;13:881284. doi: 10.3389/fgene.2022.881284. eCollection 2022.
Since the introduction of cell-free (cf) DNA analysis, Non-Invasive Prenatal Testing (NIPT) underwent a deep revolution. Pregnancies at high risk for common fetal aneuploidies can now be easily identified through the analysis of chromosome-derived components found in maternal circulation, with the highest sensitivity and specificity currently available. Consequently, the last decade has witnessed a widespread growth in cfDNA-based NIPT use, enough to be often considered an alternative method to other screening modalities. Nevertheless, the use of NIPT in clinical practice is still not devoid of discordant results. Hereby, we report a case of confined placental mosaicism (CPM) in which a NIPT false-positive result for trisomy 13 required not only amniocentesis but also cordocentesis, to rule out the fetal aneuploidy, with the additional support of molecular cytogenetics on placental DNA at delivery. Relevant aspects allowing for precision genetic diagnosis and counselling, including the number of analysed metaphases on the different fetal cells compartments and a repeated multidisciplinary evaluation, are discussed.
自从无细胞（cf）DNA分析技术问世以来，无创产前检测（NIPT）经历了一场深刻的变革。现在，通过分析母体循环中发现的染色体衍生成分，可以轻松识别常见胎儿非整倍体高风险妊娠，其灵敏度和特异性是目前可用检测方法中最高的。因此，在过去十年中，基于cfDNA的NIPT使用量广泛增长，常被视为其他筛查方式的替代方法。然而，NIPT在临床实践中的应用仍存在不一致的结果。在此，我们报告一例局限性胎盘嵌合体（CPM）病例，其中13三体的NIPT假阳性结果不仅需要羊水穿刺，还需要脐血穿刺来排除胎儿非整倍体，分娩时对胎盘DNA进行分子细胞遗传学分析提供了额外支持。本文讨论了实现精准基因诊断和咨询的相关方面，包括不同胎儿细胞区室的分析中期数量以及反复的多学科评估。
