Detecting mosaicism in trophectoderm biopsies: current challenges and future possibilities.
Detecting mosaicism in trophectoderm biopsies: current challenges and future possibilities.
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DOI：
10.1093/humrep/dew250
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发表时间：
2017-03-01
期刊：
影响因子：
--
通讯作者：
Treff N
中科院分区：
文献类型：
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作者：
Capalbo A;Ubaldi FM;Rienzi L;Scott R;Treff N
胚胎嵌合被定义为胚胎内存在核型不同的细胞系，经常有报道称其在 IVF 衍生的植入前胚胎中发生率很高，并且被认为是常规应用 PGD 治疗非整倍体 (PGD-A) 的主要生物学限制之一。事实上，据报道，植入前胚胎中嵌合体的发生率为 4% 至 90%。然而，这些数据与临床妊娠中已知的数据形成鲜明对比，在不到 0.5% 的病例中观察到真正的胎儿嵌合体。在这里，我们挑战了先前在植入前胚胎中的观察结果，提出了另一种观点，该观点也考虑了诊断嵌合体的技术变异的影响，作为导致高估胚胎嵌合体发生率的一个可能原因。尽管囊胚中可能存在整倍体/非整倍体嵌合体，但在单个滋养外胚层活检中检测到这种现象的可能性代表了改进 PGD-A 实践的当代挑战。本意见书的目的是对文献进行批判性回顾，提供数据的可能替代解释，并讨论诊断 PGD-A 周期中镶嵌现象的未来挑战。
Embryonic mosaicism, defined as the presence of karyotypically distinct cell lines within an embryo, has been frequently reported with a high incidence in preimplantation embryos derived from IVF and is thought to be one of the major biological limitations for the routine application of PGD for aneuploidies (PGD-A). The incidence of mosaicism in preimplantation embryos is in fact reported to be between 4 and 90%. However, these data are in sharp contrast with what is known from clinical pregnancies, where true foetal mosaicism is observed in less than 0.5% of cases. Here, we challenge these previous observations in preimplantation embryos, presenting an alternative perspective, which also considers the impact of technical variation to diagnose mosaicism as one possible cause contributing to overestimation of the incidence of mosaicism in embryos. Although euploid/aneuploid mosaicism may be present in blastocysts, the possibility of detecting this phenomenon within a single trophectoderm biopsy represents a contemporary challenge to bring about improvement to the practice of PGD-A. The purpose of this opinion paper is to provide a critical review of the literature, provide a possible alternative interpretation of the data, and discuss future challenges with diagnosing mosaicism in PGD-A cycles.