Department of Obstetrics and Gynecology, National Taiwan University Hospital, Taipei, Taiwan.
Taiwan J Obstet Gynecol. 2011 Mar;50(1):74-8. doi: 10.1016/j.tjog.2011.01.040.
Preimplantation genetic diagnosis (PGD) offers an alternative for women to carry an unaffected fetus risk of hereditary diseases. Trophectoderm biopsy may provide more cells for accurate diagnosis. However, the time allowed for transportation of the specimens to the laboratory and performance of molecular diagnosis is limited. We designed a PGD program of trophectoderm biopsy, vitrification of blastocysts, whole genome amplification (WGA), double confirmatory genotypings, and thawed embryo transfer.
We conducted this strategy for a woman of familial neurofibromatosis type I (NF-1). She had a genotype of heterozygous c.6709C>T mutation of NF1 gene. Trophectoderm biopsies were performed on 13 blastocysts. Then, individual blastocyst was vitrified. WGA was performed for the samples, followed by genotypings with both real-time polymerase chain reaction and sequencing. Eight embryos were diagnosed as unaffected, four were affected, and one was inconclusive because of allele drop-out. In the next cycle, two unaffected blastocysts were thawed and transferred, that resulted in a singleton pregnancy. The pregnancy was confirmed as unaffected by means of chorionic villi sampling.
We first demonstrate successful application of blastocyst biopsy, vitrification, WGA, and thawed embryo transfer for PGD of a monogenic disease. Vitrification of blastocysts after biopsy permits sufficient time for shipment of samples and operation of molecular diagnosis.
胚胎植入前遗传学诊断 (PGD) 为携带遗传性疾病风险的女性提供了一种选择，使其能够孕育正常胎儿。滋养外胚层活检可以提供更多的细胞，从而进行更准确的诊断。然而，标本运输到实验室进行分子诊断的时间是有限的。我们设计了一种滋养外胚层活检、囊胚玻璃化、全基因组扩增 (WGA)、双重确认基因型分析和冻融胚胎移植的 PGD 方案。
我们对一名家族性 I 型神经纤维瘤病 (NF-1) 女性采用了该策略。她的 NF1 基因突变杂合型为 c.6709C>T。对 13 个囊胚进行了滋养外胚层活检。然后，将单个囊胚进行玻璃化处理。对样本进行 WGA 后，采用实时聚合酶链反应和测序进行基因型分析。8 个胚胎被诊断为正常，4 个胚胎为异常，1 个胚胎因等位基因丢失而无法确定。在下一个周期中，解冻并移植了两个正常的囊胚，成功妊娠。通过绒毛膜活检确认胎儿正常。
我们首次成功应用囊胚活检、玻璃化、WGA 和冻融胚胎移植对单基因疾病进行 PGD。活检后囊胚的玻璃化处理为标本运输和分子诊断留出了足够的时间。
