IVI-RMA New Jersey, Basking Ridge, NJ, USA; Thomas Jefferson College of Biomedical Sciences, Thomas Jefferson University, Philadelphia, PA, USA.
The Foundation for Embryonic Competence, Basking Ridge, NJ, USA.
Reprod Biomed Online. 2018 Apr;36(4):388-395. doi: 10.1016/j.rbmo.2017.12.015. Epub 2018 Jan 2.
Triploidy accounts for ~2% of natural pregnancies and 15% of cytogenetically abnormal miscarriages. This study aimed to validate triploidy detection in human blastocysts, its frequency and parental origin using genotyping data generated in parallel with chromosome copy number analysis by a targeted next generation sequencing (tNGS)-based comprehensive chromosome screening platform. Phase 1: diploid and triploid control samples were blinded, sequenced by tNGS and karyotype predictions compared for accuracy. Phase 2: tNGS was used to calculate the frequency of triploidy in 18,791 human blastocysts from trophectoderm (TE) biopsies. Phase 3: parental origin of the inherited extra alleles was evaluated by sequencing parental gDNA to validate triploidy predictions from Phase 2. All karyotypes and ploidy in controls from Phase 1 were correctly predicted by two independent methods. A blastocyst triploidy frequency of 0.474% (89/18,791) was observed in Phase 2 of the study. Finally, five suspected triploid blastocysts with parental DNA available were confirmed to be triploid and of maternal origin. tNGS provides higher sequencing depth in contrast to other contemporary NGS platforms, allowing for accurate single nucleotide polymorphism calling and accurate detection of triploidy in TE biopsies. Triploidy in intracytoplasmic sperm injection-derived blastocysts is rare and mostly of maternal origin.
三倍体占自然妊娠的~2%和 15%的核型异常流产。本研究旨在通过靶向下一代测序（tNGS）的综合染色体筛查平台生成的与染色体拷贝数分析并行的基因分型数据，验证人类囊胚中的三倍体检测、其频率和亲本来源。第 1 阶段：将二倍体和三倍体对照样本设盲，通过 tNGS 测序，并对核型预测进行比较以评估准确性。第 2 阶段：使用 tNGS 计算 18791 个人类囊胚滋养外胚层（TE）活检中的三倍体频率。第 3 阶段：通过测序父源 gDNA 来评估遗传额外等位基因的亲本来源，以验证第 2 阶段的三倍体预测。第 1 阶段对照中的所有核型和倍性均通过两种独立方法正确预测。在研究的第 2 阶段观察到囊胚三倍体频率为 0.474%（89/18791）。最后，对 5 个具有可用父源 DNA 的疑似三倍体囊胚进行了确认，均为三倍体，且为母源来源。tNGS 与其他当代 NGS 平台相比提供了更高的测序深度，允许准确的单核苷酸多态性调用，并准确检测 TE 活检中的三倍体。ICSI 衍生囊胚中的三倍体罕见，且主要为母源来源。
