Reproductive Biology Laboratory, Amsterdam UMC Location University of Amsterdam, Amsterdam, The Netherlands.
Amsterdam Reproduction and Development Research Institute, Amsterdam, The Netherlands.
Prenat Diagn. 2022 Dec;42(13):1612-1621. doi: 10.1002/pd.6260. Epub 2022 Nov 12.
Noninvasive Prenatal Diagnosis has recently been introduced for a limited number of monogenetic disorders. However, the majority of DNA diagnostics still require fetal material obtained using an invasive test. Recently, a novel technique, TRIC (Trophoblast Retrieval and Isolation from the Cervix), has been described, which collects fetal trophoblast cells by endocervical sampling. Since this technique has not been successfully replicated by other groups, we aimed to achieve this in the current study.
Pregnant women referred for transvaginal chorionic villous sampling (CVS) were asked for an endocervical sample prior to CVS. The TRIC samples were processed to isolate trophoblast DNA. TRIC DNA was used in ForenSeq to determine the amount of maternal DNA contamination, and for Sanger sequencing in case of a monogenic disorder.
23%-44% of samples had a sufficiently high fetal DNA fraction to allow genetic testing, as calculated by Sanger sequencing and ForenSeq, respectively.
We have been able to successfully replicate the TRIC protocol, although with a much lower success rate as described by the original study performing TRIC. As we obtained the samples in the actual clinical setting envisioned, the method in its current setup is not advisable for use in prenatal diagnostics.
最近已经引入了用于少数单基因疾病的非侵入性产前诊断。 然而，大多数 DNA 诊断仍需要使用侵入性测试获得胎儿材料。 最近，描述了一种新的技术 TRIC（宫颈内胎儿滋养层细胞的回收和分离），该技术通过经阴道取样收集胎儿滋养层细胞。 由于该技术尚未被其他小组成功复制，我们旨在本研究中实现这一目标。
向因经阴道绒毛膜绒毛取样（CVS）而就诊的孕妇在 CVS 前要求进行经阴道取样。 将 TRIC 样本进行处理以分离出滋养层 DNA。 将 TRIC DNA 用于 ForenSeq 以确定母体 DNA 污染的量，并在存在单基因疾病的情况下用于 Sanger 测序。
根据 Sanger 测序和 ForenSeq 的计算，分别有 23%-44%的样本具有足够高的胎儿 DNA 分数以允许进行基因测试。
尽管与进行 TRIC 的原始研究相比，我们的成功率要低得多，但我们已经成功复制了 TRIC 方案。 由于我们在实际的临床环境中获得了样本，因此该方法在其当前设置中不适合用于产前诊断。
